If your in the Military, let me say Thank you for Serving!
now.....
Ditto on the aftermarket block...... unless.... you can find a late 60's 351 block (much stronger than later blocks, thicker casting) or a mexican 302 block from the 60's..... (same deal) the stock 5.0 blocks are somewhat sturdy, but wont take much to break if you accidentally get into detonation, etc.
Ditto on the heads as well, I would watch Racingjunk.com, you can usually find some really nice heads on there for not too much, sometimes complete engines too.
For example, the current setup Im working on is a 9.5:1 compression, 310 CI Boss block with forged eagle crank, forged H beam rods, DSS custom forged pistons, Trick Flow 210cc TW heads, a parker funnelweb converted to EFI, a wilsons manifolds 90mm adapter elbow, 90mm throttle body, a Vortech S trim (for now), 60# injectors and a blow thru PMAS HPX. the car will have a 255 in tank pump, Trex external, and aftermarket fuel rails too. I plan to upgrade the rest of the fuel system eventually. I am running a stock, although smoothed and worked over, oil pump, and a custom "blower" grind Lunati hyd roller cam.
I hope this gives you a good idea of what combos work well (i havent run mine, but it has been a proven combo before). post up with any questions, there are a lot of guys here that have a lot of experience, and would be glad to help!