DJE,
Building an M14 type is not hard as long as you have the right tools for installing the barrel, finish reaming, headspacing, and pressing on the op-rod guide. After that it's merely a matter of putting the parts together.
The problem lies in finding all USGI parts. They are now getting harder and harder to find and the prices of late have been really rocketing upwards. Seems like the last USGI M14 parts kit I saw was selling for somewhere around $600+, less receiver of course. If you can't find a decent kit and have to buy it all a piece at a time expect to pay a lot more than that by the time you are done.
If you really want an M14 type, check with the "other" buillders out there..... like Fulton Armory, Armscorp, Smith Enterpirses, West Texas Ordnance, etc. These guys have great reps and will build you a rifle that will work and last.
On the other hand..... Springfield Armory DOES have a lifetime warranty on their products. If you have problesms it can always be sent in and fixed-replaced. Any few problem parts can always be replaced with a USGI part as a permanent cure.
An alternate to the whole idea..... Get an nice M1 Garand from the CMP for $400, send it off to have it re-barreled to .308.
.308 Garands are the best thing since sliced bread and bottled beer....
Just my thoughts,
Swampy
Garands forever