If your using stock ve cams the gtir pistons will be fine. If your using any other cam you need to notch the pistons or just better off going cp pistons. CP's are good to 700whp with standard pins and well over that with upgraded wrist pins.
With what your shooting for as long as your using the standard cams the gtir's will be good.
Anything else or any future plans of uprading you might as well get the VE specific CP pistons that have the valve reliefs and like Jaime said, it gives your more tuning cusion if something goes wrong.
My cp's have taken a lot of abuse over the 3 years they have been in my motor. Melted holes in the exhaust valves and blew almost every ground strap off my plugs when my motor went lean from my fuel pressure dumping and the pistons didnt have a mark on them. Put a new head on and it was like new.
Then same thing happened again because i didnt realize at the time it was a problem with the regulator, blew two ground straps off the plugs and damaged the top rings of the pistons but the pistons themselves were still perfect. lol. The CP's are very very strong. They dont have a single detonation mark on them even though there was obviously detonation.