And dont forget to send those heads out to a shop to get checked. Hopefully they arent warped and if they are, hopefully they can be fixed. At any rate, I wouldnt bolt those heads back on until they were checked out by a machine shop.
Also, good idea to change the O2 sensors, or if your cheap, at least pull them out and clean them with something good. They dont like antifreeze. Then make sure your cats arent clogged up from the antifreeze blowing through them. Also a waterpump and thermostat are good ideas, along with flushing the snot out of radiator. Then make sure you dont have any coolant in the crankcase, massive flushing prior to startup and a few oil changes once you get it running should help this. Its not that bad of a job and there are tons of people here with parts should you need em. good luck.