The RST is good for 700. The issue of stepping up in holding power is the elimination of the forgiveness. Meaning the clutch becomes harsh and more prone to chatter. Drag racing it doesn't matter as you want to transmit all the power rearward. For the street it's a different story. It all is what you want to deal with. I have driven the RST clutch in a 500 horsepower LSX engine Camaro and the clutch is a amazing. Smooth as silk and I have to say after seeing it at SEMA in '06, it;s a great combination of organic and composite material that really work. Clutch pressure is still light enough that you can drive it (shifting) all day.
Other folks make twin discs so check them out, I can only recommend what I've driven. Good luck.
