I've had mixed luck with eBay parts. I bought a set of E34 front suspension parts from FCP Euro, because I'd heard good things on Volvo forums. I had to return the "M5" alu thrust arms as they were nearly 1" too long. WTH?!? How hard is it to get the size right? The rest of it was generic (Moog, TRW?), but it made a big improvement. I'm not sure how long it lasted...I traded that car for a pair of E30s less than a year later.
I hate dealing with suspension work; I either postpone it or just do it right once and leave it. I've used generic, Meyle and Lemforder. Meyle used to be a good bit cheaper, but they're almost as much as Lemfoerder now. Best price I found on the Lemforder control arm
is $101 at Blunttech. ECS
isn't too far behind at $108. ECS also
has a full kit for $319. I'm unsure of brand.
I'd recommend taking the car to a good indie shop and getting their opinion on the front suspension. Personally, I'd replace the steering links first. They're pretty easy to do, and tend to wear out faster than the control arm balljoints. Just measure the arms before pulling them, and match the length when installing the new parts. It'll get you in the ballpark. If the car is still sloppy after that, go after the control arms and bushings next. Then get the alignment you'll need.
It's a shame that the front control arm bushings are such a PITA. Those wear out the fastest of all, but once you've installed them, they can't be removed again if you install new arms later. The solid M3 bushings are a big improvement. I'd recommend the centered ones. The offsets make the car feel better but tend to chew up tires in street driving. I've always been reluctant to use urethane parts, but they hav ethe big advantage of being reusable. I've been tempted by the
Treehouse Racing eyeballs, but $200 is a bit rich for me.