Before you shell out $$$ to a machine shop, ask them what it will take to bring the engine into spec for rebuilding. If it has to be bored - you are looking at a new set of pistons minimum. If the crank needs cut to much you might be looking at a new crank, but many shops will have good blanks (used one that is in good shape) that can be turned .010 to bring them into spec. Since the block has been fryed, you should consider getting it magged, and line bored. It is possible the block could just be a disaster. At any rate, ask the shop to take a look at it and see if it is economically viable to machine it for rebuilding. Have them mag it after it comes out of the tank, to keep your costs down if it is cracked. Then you'll only be paying for a tank job and a mag job that you get to have the shop throw away for you. Ask about brass vs steel freeze plugs. And don't forget to have the shop install your cam bearings for you. It's just safer to let a shop put them in.

Godd luck.