Well here is pretty much what remains out there:
Service Grade M1 Garand:
Service Grade Rifles show less wear and better appearance than Field or Rack Grades. Good to very good condition. Rifle wear will be exhibited by worn and mixed colors of the parkerized finish. There may be some minor pitting on the metal parts. Wood will be either Walnut, Birch, Beech or other variety and will be basically sound but may have minor hairline cracks, dings, scratches and gouges. Wood may not match in color or type of wood. Wood may be of new production on Service Grade Garands. Bores will be generally good with only minor imperfections. The barrel crown may be nicked, but the muzzle will gauge "3 or less" and the throat erosion will gauge less than 5.
So overall you will be getting a pretty good rifle for your buck. Certainly fine for local club match shooting. Most of the service grade rifles I have seen of late have been some really nice rifles well exceeding the above quote.
Looking a little more into the Service Grades:
M1 Garand, HRA (Harrington & Richardson)
Service Grade $625 Effective 1-3-2012
S&H $24.95 per rifle
Then we have:
M1 Garand, Service Grade HRA (Harrington & Richardson) Special.
Allow 60-120 days for delivery.
HRA collector grade metal in excellent almost new condition. Walnut stocks and handguards and associated hardware are new manufacture. NOT original HRA manufacture.
$950 Effective 1-3-2012
S&H $24.95 per rifle
The latter gets you all new lumber and associated hardware. However, many of the service grades I have seen for the $625 price have also had new lumber. That becomes a craps shoot. You won't go wrong with either and both flavors are in the original 30-06 chambering. The latter $950 rifles also seem to have better all around metal.
Moving along to the:
Special Grade M1 Garand
Here you have both chambering flavors. You can have 30-06 or the 308 Winchester (7.62 NATO). Your $995 S&H $24.95 per rifle gets you:
M1 Garand, CMP Special (.30-06)
Allow 120-180 days for delivery.
M1 Garand Springfield Armory receiver. This is a completely refurbished rifle consisting of an original M1 Garand Springfield receiver, new production Criterion barrel, new production American Walnut stock and handguards, and new web sling. Receiver and most other parts are refinished USGI, but some parts may be new manufacture.
or....
M1 Garand, CMP Special (.308)
Allow 120-180 days for delivery.
M1 Garand Springfield Armory receiver. This is a completely refurbished rifle consisting of an original M1 Garand Springfield receiver, new production Criterion barrel, new production American Walnut stock and handguards, and new web sling. Receiver and most other parts are refinished USGI, but some parts may be new manufacture. A .308 spacer block is installed to prevent the loading of a .30-06 round into the chamber.
As to the 30-06 verse 7.62 NATO chambering that is purely your call. My observation is the 308 chambering offers less recoil at a small cost of a few hundred FPS of muzzle velocity in the standard loadings. Nothing that will really matter much. Both of the special grade rifles will be excellent rifles that have been totally reworked and include a new barrel.
Also along the lines of chamberings be it 30-06 Springfield or 308 Winchester there are limits as to what you can shoot. The selected ammunition needs to conform to the M1 Garand gas system. A few ammunition manufacturers market ammunition tailored to the M1 Garand and a few loading manuals call out specific loadings tailored for the M1 Garand rifle in either chambering. There are also a variety of gas plug screws out there such as
this one or also
this one. I suggest you read the links to get an overview of what is going on with gas systems.
What you choose to buy is a matter of your personal taste and I guess your pocket book. I would make a decision and move on it as they won't be around forever and CMP is your overall best bet. Personally I would go with a special grade in 308 but what you want and not what I would get is what's important.
Just My Take....
Ron