If you want to spend the money on some bullshit ebay kit...take your chance. Remember the saying "If it sounds too good to be true, it probably is." That applies here. The kits are that stupid cheap save money by using thinner gauge steel for their parts. SO they'll crack and leak and shit like that over time. Your money could be much better spent elsewhere. A fox kit will work usually as far as the hotside goes but it COULD interfere with some of your accessories.
HONESTLY, the BEST kit and cheapest is one made specifically for your car. I've got more than a couple of friends running a flipped shorty setup on 900+hp cars. The big money is spent on the turbo of choice...everything else is pretty much the same cost whether your making 300rwhp or 1,000rwhp.