[omegaman]

I have Pfadt springs only, but honestly most of the the manufacturers you reference are good. Toss Hotchkis in this group as well. There is not much tech going into sport springs and sways so all these manufactures will be very close with spring rates and size and composition of the sway bars. The really big thing for you to avoid is eBay - avoid the chinese knock-offs.

I say go with the speed shop and manufacturer who gives you the best deal.