I was one of the first people that jumped on the BMW Perf V1s when the price got stupid cheap- 133 bucks. Have had them for the past 40,000 miles. They tightened the car up substantially (they replaced 80k old dead sport struts).
If they are stil avail I would find them.
Plus I think heard they are bilsteins valved by bmw and painted black, so they should last a damn long time.