I run the KB Hyper .40 over, only off the shelf pistons i could find, they sit .022 out of the deck, and i run a .066 head gasket for 10-1 with the eddy heads and the 63cc chambers
cometic will make any gasket thickness you want....research the pistons and rings and find what you like. a set of custom gaskets are about $175...and are reusable according to cometic....