I just replaced the clutch on my wife's MS6. I ordered an ACT full face stage 1 and when I opened the box, mid way through the replacement, I found that they had shipped a 6 puck (sprung). Her old clutch was toast, nothing but dust left, so i put the 6 puck in without explaining it to her. It doesn't feel to bad and is working really well with 1,200 miles so far. I don't think she would have even known there was anything but an OEM replacement if my friends had not spilled the beans.
The install was not easy. I elected to pull the motor rather than drop the subframe and all associated stuff. Either way, count on spending the greater part of a weekend on it.
To the OP, figure 900-1K for install at a shop. I think the dealer bills 9 hrs for this job so an independent shop might be a little cheaper. You can find an ACT clutch kit for 800 or so. You will need to replace the clutch and flywheel. The ACT kit includes a flywheel. Not sure about the clutchmasters kit. I remember reading about it, but don't know if they have actually released a kit yet or they are still in testing.