I don't have an answer, but I'm very interested as well. I've read some very positive reviews of the IAI M1 Carbines (supposed to be a little more accurate than the original GI carbines). But I don't care for the looks of the steel handguard, and a walnut replacement is fairly costly (I think IAI quoted me $40 or $50 for just the handguard). If I wanted an M1 carbine mostly to use and shoot, I'd probably go with the IAI. But the historical interest is a big part of it for me, so I'm leaning more toward a G.I. parts gun in standard military configuration (wood handguard).
I would like to know of a good source of M1 carbines. An outfit in Sacramento California advertises "U.S. Issue .30 Cal M-1 Carbines" in Shotgun News for $159.95 - unfortunately, they can only be sold to law enforcement (I think they were "re-imported" into the U.S. and that was an import requirement). It is frustrating that similar carbines sell for $500 or more to civilians.
Doug