You have to shop but also it pays to know who the reputable manufacturers are. try to find European manufacturers like Lemforder, ATE, Bosch, Bilstein etc. I would avoid URO (U'll Replace Often) and China for now. Although I suspect many of the "European" parts are now made in China the European companies seem to be holding the line on quality control.
Although there can be some great deals on eBay there are also some huge markups as well. I was looking the other day and someone was selling rubber motor mounts that are normally $25 to $100 each for $995 a pair.
do a thorough inspection for rust before you begin as it will help you decide how deep you want to go.