i don't know what the spring rates of ANY of those springs even are... I think the difference is more in spring length than rate. Call up the manufacturers and ask for rates, and I'll be able to give you a little more info from there.
If you really want to customize your spring rates, you'll need to go with ground-control (or other coilovers with multiple spring rate availability). There is nothing inherently poor-riding about coilovers... your previous experience was probably due either to poor quality coilovers, inapropriate spring rates, or mismatched shocks.
:edit: Looking at your sig, I think I may have found your problem. I wouldn't expect "dropzone" struts to ride or handle worth a damn.