FWIW, and with full knowledge that this is not 100% kosher:

B16 pistons will work, but you will need to use a thicker head gasket to bring the compression back down (~1.5mm will keep you legal with JDM or USDM B16) but they have a dome. B18C1 pistons are dished slighly and will also fit. no compression worries there, but again, technically NOT the same as the B17, though very close. it should be easier to source B18Ci (GSR) and B16 (civic/del sol Si) pistons in various overbore sizes as they are far less rare than your B17.

if you don't run the ARRC nor a very competitive series, no one should be too unhappy about your using these parts so long as you keep the CR to 9.56 +0.5/-0.

Handy calculator at: http://www.zealautowerks.com/