Ebola: cleaning of protective suit
Notice: the only select agent I've worked with is VSV which was a USDA select pathogen (not as big of a concern for humans).  

TLDR:  It would provide some protection, but I would be most worried about a false sense of security.  It would unlikely be up to rated standards, but it would likely be better than a t-shirt.

First let's start with ebolaviruses.

Ebola, like HIV and many other viruses, doesn't do well outside a host.  This might be because the protein structures beneficial in the host are not the same as needed for stability in exposed air and room temperature.  A counter example of a very stable virus would be something like human rhino virus (HRV).  If HRV was compared to be like a rock, ebola would be over cooked spaghetti.

Certainly the virus has to maintain some stability in the environment, otherwise it wouldn't succeed evolutionary.  As I'm sure you've heard on the news, ebola is spread by contact with contaminated fluids.  I would like to point out a wonderful info-graphic that was made for public consumption, especially the image on viral life cycle:



Assuming that you're not going splunking in bat inhabited caves in West Africa, it's safe to assume that what we are worried about is human to human transmission through infectious fluids.  Ebola actual isn't that stable in water, so just soaking a surface in water and a little oil might help you out (if you don't have bleach handy).  I want to be clear that I'm not recommending this, in reality you should just avoid contaminated objects.  I think that we have clearly established that what we're really concerned about is infectious bodily fluid.

This leads me to the wonderful note by Jose Martin-Moreno titled "Is respiratory protection appropriate in the Ebola response?"  I don't think I can express the problem better than he can, so hopefully I will be allowed a substantial quote:


  This transmission [of ebola] occurs via close family contact or in
  health-care settings, particularly when placing orotracheal intubation
  or when caring for a patient who is vomiting or bleeding. Ebola is
  rarely transmitted via an airborne route. Although these routes of
  transmission are well known, most agencies, including governmental
  agencies responsible for repatriating western patients, apply
  infection-control measures appropriate for airborne diseases.
  Excessive precautions could offer reassurance to those responding to
  Ebola, yet complete respiratory protection is expensive,
  uncomfortable, and unaffordable for countries that are the most
  affected. Worse, such an approach suggests that the only defence is
  individual protective equipment, which is inaccessible to the general
  population. Moreover, the image of workers with spectacular protective
  clothing might contribute to the panic in some communities. If this
  leads people to flee affected areas it could increase the spread of
  infection.


With that said, all your full face gas mask is going to help with is prevention of fluids from hitting your head.  You could probably take the actual filters out to breath more easily (I find breathing in them a giant pain).  And as @Chris pointed out, they are easily clogged which could necessitate the need to take off the whole mask (which might be doing some good) to prevent suffocation.

Moving to hazmat suit.

It's actually good news that you don't need the air containment of the suit, as that's the hardest element to maintain.  To state the obvious, the main purpose of the suit is to prevent your body from coming in contact with infectious fluids (in this case).  To do that you don't need to be in positive pressure personnel suit (PPPE), or follow BSL4 considerations.  The respiratory concerns from in an BSL4 environment come from other select agents, and the personal working in such a facility are going to be doing very different activities from what you should be doing as person trying to avoid an outbreak (they could be purposefully growing up purified high-titer virus stocks and running around with pointy things as an example).

Here I'm going to run into citation problems because no one (that I could find) has tested the kind of scenario I'm about to discuss, so it should be seen as informed conjecture.  Assuming yous suit is actually an analog of a Tychem QC suit, it's probably not a rated OSHA unit (A-D), but that doesn't necessarily matter.

On it's first use it would likely be sufficient to protect against incidental exposure.  Let's assume for the sake of argument that you didn't run into any Ebola when you used it as a costume, and don't the next time you put it on.  At this point decontamination (decon) isn't the concern, failure of the material is.  In other words, are you sure you don't have any holes, tears or cracks in the material?  I think this is going to be the real limiting factor in the life of the suit.  Using good old fashioned duct tape will be give you a few more uses, but the suits are just not designed to last through prolonged use.

Now let's assume the worst and that you get substantial blood splatter on you (while wearing your suit) from an ebola patient.  And not a little that could easily be wiped of with a spray bottle of 10% bleach and a paper towel (how most decon could be done).  Instead let's assume you're standing next to someone who suffers a traumatic injury on top of having ebola virus disease (EVD).  I'm imagining something like a point-blank shotgun wound or, given the probability of this scenario, a falling grand piano. In this case, you're going to want to decontaminate the suit before you take it off, which is the same thing professionals are going to do.

If you're friends with your local fire department, and you live in an area with a large enough population to have a HAZMAT team, you can probably get them to at least give you a run through of how it's done in ideal conditions.  YouTube videos are also not hard to find, just search JESTC and decontamination.

Presumably you would have a hard time going through several rinse and wash steps, but you would want emulate this as much as possible.  With ebola, you would be fine to decontaminate with a 10% bleach solution (or if you use bargain/cheap bleach 15%).  The trick is that you would want to do it a few times, and with a friend (also hopefully in a suit).  Thus if you got two generic soap sprayers, filled one with 10% bleach, and the other with water, and then alternated spraying your partner with bleach and water, wiping down as you went, you should be able to decon the suit pretty well.  If possible you're going to want to collect all the run off an rinsate.  Again professionals tend to use actual kiddie pools for this. 

But just the act of using so much bleach on the suit is going to weaken the fabric, again leading to the principle problem of failure of the fabric. Thus I would be worried that such a suit would provide a false sense of security, leading one to go into dangerous infectious environments when one shouldn't.  Just avoiding and going away from contaminated individuals is going to be the best solution, regardless of a suit.

I considered going into why I think it's highly unlikely that any of the ebolaviruses would evolve to be airborne, but I consider that outside the scope of the question.