One thing to keep in mind when going to a twin disk system is that an aluminum flywheel is highly advised. The lighter flywheel helps to offset the extra weight of the added clutch disks and reduces the impact on the transmission, which helps to keep it alive.
I had a really bad experience with McLeod's original street twin and their customer service, but ultimately they did resolve it after a lot of ass-pain dealing with them. The original street twin has a light to moderate pedal, a smooth grab, and can hold more power than even the RXT. It's also one of the priciest on the market, but the feel once its right is awesome. It's maximum shift speed is only around or a little less than 7k RPM. I understand that the RST and RXT twins are better at dealing with higher revs. I would not recommend these clutches based on your needs. While nice, I wouldn't encourage you to go for a twin-disk, because based on your power level and transmission, it's far too much money and way overkill.