You aren't really going to gain much by going to the euro pistons. There is more power to be had from the engine with the right cam. I would talk with John from
Dougherty Racing Cams about what cam to go with. He needs to know what you want from the engine and will help guide you to which cam will work. John posts here as Camgrinder. Part of that depends on if you need to comply with emissions.
Also a top end may be in order as you will have it all apart and with the low miles shouldn't have to replace valves so pretty much the guides and labor. Also replace the lower 12 dilavar studs with steel. I had two broken at 88,000 miles. Were you looking to just change the pistons or cylinders and pistons?
Check out this thread on the 10.3:1 euro pistons
http://forums.pelicanparts.com/911-engine-rebuilding-forum/260251-carrera-rebuild-10-3-pistons-cylinders.html