Where do i get an HTC-Hero ROM I have an HTC Hero Android Version:2.3.3, i want to figure out if i can downgraded it to a previous version that the Hero can actually handle.  


I don't know if my android is rooted, and not sure how to find out 
I don't know if my phone is upgradable/downgradeable or not  and
and I  have no idea Where I can get a nice clean ROM for my phone
It's probably rooted.  If not, then it was in order to install 2.3, and it can be rooted again.  If you have the SuperUser app, that should be a clear indication that it's rooted.

You should definitely be able to downgrade.

The best source for ROMs is generally the Android Development subforum for a particular device on XDA.  In this case, this subforum.