Just throwing this out there, but typically a bike shop will throw in a fitting if you're buying a bike, but will charge otherwise. Of course every shop is different, but you probably don't want to spend as much on a fitting as you do on your bike.
I found this site to be decent in determining fit, at least as far as road bikes go.
http://www.competitivecyclist.com/za...LCULATOR_INTRO
It's not going to be as accurate as being professionally fitted, but the price is right.