Along with Andys question, can you provide engine specs, as IMHO It would be a good idea to formulate a long term plan hear. If that works for you, selecting parts to compliment your end goal will help you get there and save $$ in the process.
Right now i am wondering how much torque your trans can take, bore /stroke combo, etc. For a glide/bracket car, too many cubes is about right. That may be a better place to start? Especially if there is a crank/rod combo that will use current pistons.
An example would be a 572 shortblock with small heads, like ported SRs. Low maintenance, tons of torque, all done by 6500 rpm?