I haven't bought anything for my car, bit I've bought some bits for the missus's Bimmer (clear indicators, repeaters, light clusters etc).
All were spot on, no problems.
I would have no qualms at all about using ebay. My only advice is to keep an eye on the seller rating - try and stick to sellers who have sold to a decent number of people within the last 6 months, with a very high (95% plus) rating.