Hypereutectic pistons will take as much power as an aftermarket piston, however they are much less resistant to detonation. They are more brittle, so your tune must be better and/or less aggressive. Good tune and you'll bend stock rods before harming a stock piston.

 

You'll end up worse off in the long run by pulling such a low mileage motor apart and slapping it back together with a bunch of parts that aren't anywhere close to needing replacement. I'd throw your cam in there and choice of springs/pushrods, trunion upgrade if you feel like it, compression check and put it in the truck untouched. At 68k miles that thing is practically brand new still. My 01 z-28 had almost 300k on the clock when I sold it and the only thing "wrong" with the motor was a small oil leak from the rear main (go figure on an ls1).