Head advice

I'd use RHS (LA-X) heads. The EQ's are real good heads too but their magnum valve train only. IMO the shaft rocker system on a LA head is superior and sometimes cheaper. You also need oil through lifters when you use EQ's. Learned all this the hard way, LOL

As for the head gaskets your best bet is to measure how far down in the hole the pistons are and see if you can find some gaskets that'll gets you as close to .040" between the tops of the pistons and the closed part of the chamber on the heads as you can get. That'll give you a good amount of compression and quench to resist detonation. Most likely your going to need the thinnest gaskets you can find because if the block wasn't milled the pistons are usually down in the hole .015-.020"