I just installed the airlift 1000 to because I have the same problem you do. I just bought a versahaul to put my 600CC bike on the back.
I've installed it myself, but haven't put the bike on just yet. You can install youself easily, but two things to note:
1. You DON'T need to remove the springs like the instructions tell you to. You can deflate the bags and wedge them in.
2. You need to cut the rubber bumpers and it's a bit hard to get to cut. I took a hacksaw blade, wrapped 1/2 in paper to make a handle and then sawed it off. Do yourself a favor and go buy a proper handsaw. I saw at OSH they sell some that are perfect. The shorter the better. It's a hard rubber so take your time. I pulled the rubber mount to one side as I cut it with the other hand (you pull it away from the side you're cutting). Seemed to make it cut faster.
3. You'll need a place to mount the valve where you can add/remove air. There is a PERFECT spot on the bottom of the driver side rear bumper. You'll see a spot meant for some screw that's not there that's a perfect place to put it.
Don't bother buying a compressor either. I keep one of those minature bicycle pumps in the side rear compartment for pumping up my tires and the new air bags.