If you are going to go through the process of replacing pistons, look into Wiseco ej22t forged units. They are set up to increase the CR and are off the shelf items. They also have some that are for use with the stroker setup with the 2.5 crank. IIRC they have a different position of the wrist pin so they don't poke our of the bore with the longer stroke.
http://www.wiseco.com/Catalogs/Automotive/CompleteCatalog.pdf
Page 55
I'm piecing together my "build" too and plan on using some of the Wiseco slugs when I do.