I have an Access roll-up cover over my 2000 Dakota. I've never really liked toppers, and this was the smoothest and easiest to use cover that still held down without those really annoying snaps. Since it clamps on from the inside and rests on the rail, you can still use the outer bedside pockets (if you have them) and keep those other bedrail accessories (for the most part).
I got mine in 2003 for about $350 installed. I've seen a lot of other trucks recently with them, it's a step up from the "Truxedo" cover that has been around for a while.