I've been looking at the Procomp MX6 also, as they have the adjustability of the RS9000, and it seems as though they are built a bit better with mono-tube construction and billet aluminum bolt eyelets rather than steel.
The other benefit, they have a promo right now - buy 3 get one free, and at $89 per shock, that seems like a nice deal.
Here's the problem, the only people that I have spoken to with experience using the shocks are the guys at 4wheelparts, and they love them, but they are also the sole distributor, so some sales pitch may be expected.
I'm still looking into Bilstein before I buy.