How can I fit a Schlage lockset in my front door?
As for expanding the hole, I am still confident this post will answer your question.

Regarding the Schlage deadbolts, these are not great deadbolts.  If you really want high security, you need to look at Mult-T-Lock or Medeco.  These are far more secure for a number of reasons. First, they are made of much harder metals - if you feel them compared to another deadbolt there is a noticable weight difference.  These deadbolts also often have balls at the end that push out of the bolt when fully expanded so it cannot be forced back in. Also, the keys for these locks can only be made (not copied) by the locksmith who originally created them (each locksmith is assigned a "keyway" and is the only locksmith who can produce the keys), this is handy if you have a cleaning lady or other service person since you can rest assure they cannot make a copy of the key for their friends.  There are also metal rings you can put around a deadbolt that spin so that someone cannot use a wrench to twist if off.

If your doors hinges are on the outside then you can also look at having bolts installed on the inside of the door.  This way, if the hinges are removed (pins popped out, or blown off with a shotgun), you cannot just pull the door off.

A heaver guage strike (the metal piece that goes on top of the hole where the deadbolt goes into) with longer screws will add extra strength to the deadbolt and hamper someone knocking down the door.  

You can also place a cage in front of the door (which too has a deadbolt) but they are not attractive, and add an extra step to opening your door.

An alarm is useful but in a lot of cases, of someone knows what they want, they can be in and out before anyone responds.

A camera adds an extra layer of "don't mess with me" plus gives you a far better chance of identifying an intruder.