The M14 was never released in it's select-fire version to my knowledge. They are extremely rare.
There are other manufactureres of the M1a, other than Springfield Armory. When the military "abandoned" the M14, all of the machinery to make them was sold to Taiwan and both Norinco and Polytech made their versions. The recievers are top-knotch but the bolts are soft. So what. Bolts are easily replaced with GI bolts and you'll end up with a top-shelf M1a shooter.
I've got a Poltech. It's a tack driver well beyond the 200 yards I've shot with it. I paid $600 (private sale) at Knob Creek last October. I brought it home and headspaced it to find that I was at the limit of safety. So, I sent it out to an armorer and had a TRW bolt put in. The bolt came from LRB in Long island NY and cost me $100. I also ended up putting a NM Douglass medium-weight barrel in mine and also unified the gas. All up I've got $1000 into it and it'll outshoot any Springfield rifle, period. So, there are plenty of M1a rifles out there by both Norinico and Polytech for about $500-700 depending on condition. Freds' sells great military original M1a stocks to swap for the "sporter" stock that normally comes with the rifle. Most trigger groups are GI, too. All up, you've got a fantastic rifle that will do everything that our snipers in Iraq are using right this minute.
You can spend upward of $2000 on one of these rifles if you go the "custom" route and buy an LRB or Fulton receiver but I dont' see the reason to do that unless you are in hot competition. I took my first deer at 87 yards with iron sites this Fall with my "new" Poly.
Rome