Its just a reciever and barrel but I figured if I went that route I'd change the barrel anyway, but I've never had much experiance with an M1. I assume it wouldn't be too overly complicated to build one.
To answer your question, the CMP sells M1s and barreled receivers. You can check out the requirements at [url]www.odcmp.com[/URL]. You will need to be a member of a CMP affilitated club like the TSRA or a veteran. You should also check out the CMP Forum at their website. Lots of good info on building a rifle. They are not the easiest to build since used parts can cause timing problems. The CMP also sells some pretty nice wood for them. I picked an M1 up at their North Store a couple of years ago. Their prices are better than you'll see at a gun show.
In general I would recommend staying away from any new production Garand receiver. It's not that all of them are bad (although some are); but why bother with them when the real deal, drop-forged and machined USGI receivers are so easy to get nowadays. The USGI Garand receivers were made back when labor was much less expensive than it is now. Making a forged and machined receiver now is an expensive process. Just look at what it costs for a forged LRB M14 receiver. You're looking at about $950. Those $600 Service Grades from the CMP are a bargain. When they are gone a lot of us will be kicking ourselves for not buying one(more) when they were available.
I picked up a Garand from http://www.garandguy.com/ about a year or so ago. It had a brand new stock and a brand new citadel barrel chambered in .308 (since I didn't want another expensive caliber like 30-06). The serial number traced back to 1943. I think with a texas CHL and a membership to TSRA you can buy one from CMP and NOT have to shoot in any matches.