I think 90/10's would be a benefit to a lowered car, you won't bottom out nearly as much. They are STIFF, I got them put on over the weekend and drove it on Sunday morning, it rides like my '84 vette I used to have, except in the turns, it has some extra body roll that it didn't have with regular shocks. I'm not sure how I'd feel driving it on the streets without the front sway bar. There are different brands of the shocks, you can pick up the summit brand shocks for under $25 a piece. The competition engineering ones are around $43 a piece. I put the summits on the rear, and the competition engineering on the front. Both brands are adjustable, but you have to remove the shock to adjust it (Not a knob like a QA1).
Summit shocks: Fronts, SUM-G7600 - Rear, SUM-G7702
Competition engineering: Fronts, CEE-2600 - Rear, CEE-2720
Haven't been to the track yet, so no update on whether they worked.