LQ9 pistons vs. LQ4 pistons

I was thinking about buying a set of LQ9 pistons for my LQ4 since the compression would only be 9:4.1. After reading about someones 408 stroker making less power than they expected, is their any difference besides one being flat top and the other dish... I plan on using a 150 shot at the most. Another question, is their any difference between LQ4 rods and the LQ9 rods. Thanks guys.

Its a 2004 LQ4, the pistons are 545.00 from my work, but I'll have a local machine shops price on Monday, LOL factory parts are damn expensive for less than 60 dollars more I can go forged, so quik your saying I can keep the dished pistons and mill the heads down how much increase in compression will I pick up doing this ?