The stocks are easy to come by if you end up getting a bad stock. You might check out
http://www.e-gunparts.com for replacement parts if you find anything missing/broken etc.
If you go to your local gunshow, many times you'll find someone offering parkerization services, so no matter how bad the metal is you can clean it up and have it parkerized, and problem solved.
As far as finding the gun, gun shows are excellent places if you research what you should be spending before you show up. There's blue book values on guns if you look on Google. Gunsamerica.com looks like a good place to look for Garands.
Hope this helps