Use a Chevy sized rod, piston, pin (lighter, cheaper). Do some math and use a 6.125 rod and find the appropriate compression height piston for a 350 motor. You don't have to be exact because you will have to grind you crank to fit the smaller rod size (big end) but you can offset grind it at that time to get the deck height you want.

All this should be pretty easy for any decent machine shop.