The turbocharger purchase is one of the best ways to save money on your build. Usually the cheapest way to go about it is to find an old junkyard turbo and throw a rebuild kit at it, so this video may help you along. Sorry for the weird audio.
-It’s best to install the metal oil seal rings with the gap facing upwards, if it’s facing downwards oil can seep through a little easier and it might cause a little smoking on startup.
-For maximum longevity, it’s best if you have the turbo balanced after the rebuild. For maximum budget, I did not have it balanced. Update 7/9/2016: No problems with the turbo after about 1000 miles.