I'm sure you can find most of this information out there, but here's a quick rundown.
The 4T65E-HD (the GTP tranny) has a stronger case and different final drive ratio.
Most of the problems people run into with GTP trannys are differentials exploding or clutches simply wearing out. INTENSE has a replacement input shaft due to a number of high-horsepower cars snapping this as well.
But seeing as though you're pretty much stuck running the 4T65E, you can get the limited slip diff and hope for the best.
Since tranny heat is a killer of clutches, you would be best served by getting a tranny cooler and probably the aftermarket trans-pan. A shift kit to minimize clutch slippage would be preferred, but this may lead to breakages down the line (CV joints, etc).
My word of caution: wait for the first few CSCs to be installed, then jump in. at that cost and risk, it's not really all that cool to be the first to toast a 4T65E simply because you wanted the SC.
ferb!