Matt,
I started going nuts at the CMP North Store about a year ago - since then I have purchased 5 Garands. The first one was a SA service grade PeeWee helped me pick out, then 2 Danish Field/GI grade guns, and my last trip saw 2 greek Field/GI grade guns follow me home.
Like you - I am only interested in shooting these guns, so when I get to the store I borrow the gauges and check the ME of all the cheap guns. I've found that the Rack Grade guns are usually dogs with excessive ME, so the next step up are the Field/GI grade guns. I can usually find ones wih MEs of 2 or less, and when I have a couple I then check the TE to find guns with 3 or less.
If I happen to find a few in this manner (not all the time), I then look for good wood and finish on metal. Most of these guns will be mix masters which means they are arsenal rebuilds from all sorts of parts manufacturers - including Beretta and other foreign companies on the Greek & Danish guns.
If they there are no decent Field/GI grade guns, you will have to move up to the Service Grades. You should not have any problem finding a good shooter in this grade, you may even find a gun with some collectability. My first gun appears to be an all original SA gun from August 1945.
All 5 garands I bought shoot great, but I did have to replece the Op Spring on 3 of them because they were broken when I bought the gun (actually, one was pinched and 2 had broken coils inside the bottom of the Op rod).
If in doubt ask PeeWee or George for some help. They are both great guys that work in the store. Make sure you pick up PLENTY of surplus ammo too, as this guns can be adictive.
I should also note that the CMP has recently raised prices - rumor is they have about 50,000 Garands left, and since they sell 15,000/year, I wouldn't wait too long to buy one.
I know I will be back for a few more....
NOTE: You my notice I call one grade GI/Field grade. That's because I don't remember which one I bought. I think CMP may actually have or had both grades and I can't remember what the GI grade guns meant.
ME = Muzzle Erosion
TE = Throat Erosion
I believe ME is more important for accuracy.