ok well here is the deal man. can you use ebay stuff yes. will it last maybe? they are hit and miss. some things you dont want to trust to ebay. such as things that let the extra pressure go. cheap waste gate and cheap bov's, and couplers are not a good idea. if you have the money to spend then do it right the first time or the 2nd will cost much more. if you dont have the money to do it right the first time.... I would say dont do it. boost will cost you in the long run and you have to get plenty of upgrades to go with it.
you really need to read up on boost to make sure it is what you want. boost sounds like a good idea to everyone untill they really get into it. take your time and get the parts one at a time. many of us have been putting a kit together for a long time! myself I am getting close towards 8 months or so. but the good news is I will have the rest of my parts around 2 weeks.
make sure you get a good tune! that is key. you can run a dirty tune and blow your car up if you dont watch it. my tune is going to run me 500 bucks
but worth every cent!
what sort of power are you looking for? maybe spray would be better for ya if it is a lower number? just a thought..