For a 360 project
All 360's until the late 80's had the same head so there is no "big head". Since you are just looking for a core to rebuild there is no advantage to paying $400, even $200 for the junk yard motor is a little high. I picked up a 360 that came with an after market single plane intake for $50.
Take a look at this link. It chronicles my 360 build.
http://www.forabodiesonly.com/mopar/showthread.php?t=4798
Here is a claculator to help you figure compression
http://www.csgnetwork.com/compcalc.html
BTW, with the heads on the engine and the KB107 pistons you will have to have the block zero decked to get to 10:1 compression. Also, the KB107 pistons come in 0.020 over so if you don't need 0.030 go with the 0.020.