Well, there's a common saying....you can't have your cake and eat it too....unless your cake is shaped like a McLeod RST twin disc.
When you start getting to the 550-600hp rating, then the friction materials necessary to hold that kind of power start heading towards the exotic sides of things. I've ran those Powergrip and Powergrip HD's in a lot of cars and haven't had any chatter, but my disclaimer is that there is always the possibility with any kind of friction material other than organic/organic. The weight of the car helps a lot and lower rearend (numerically higher) gears help a lot too.
If you track the car, I would go with more clutch. I would go with either a Powergrip HD or I can do a custom McLeod clutch, with a diaphragm pressure plate and one of their 600 series discs.
The Powergrip HD would be $370 + shipping. It's rated for 650hp.