The KB pistons are nice. There is one that has a step on the top so you can set your Quench with the open chamber your heads feature. Having said that, it takes a bit more work to get the Quench set. ( Milling your heads and possibly decking the block).
I built one years ago for my late boss, it turned out at 9.4-1 with .035 Quench, it would run on almost anything you put in the tank. Also with the KB's you MUST be sure to follow the directions on top ring gap.