What amp do you use? I hate to dissapoint, but most stompboxes won't have a thick rich sound...it's all in the power of your amp.

If you leave your amp gain around half, and put a boss sd-1 or an mxr wylde overdrive on top of it, you get a HUGE, thick sound with tons of sustain and harmonics.

You'd seriously be surprised at how much distortion and sustain you can get from adding the tiniest bit of gain from a stompbox overtop and amp overdrive.