Fireball - Yes, I started with the Slee Heavy 2.5 kit. I then changed out the rear springs that came with the kit for the 864s, which are taller and stiffer. I still have the springs that came with the kit in case the ride was too jarring with the 864s, but it really hasn't been an issue. Even when I'm by myself, I'm not bothered by the stiffness - I don't even think about it. I planned on running with weights in the back, but haven't felt the need. Others have complained of the Slee Heavy Kit as being too stiff for their comfort (much less the 864s), so I'm guessing it just depends on your preference. For me, this has been a great investment with zero regrets. I'll be putting the other springs up for sale.
Slee shows that the shocks are OME 60000 and 60002 on their kits, I think that is what I have.