Custom Turbo - Who has done it

[JSeoul]

I'm not talking about an Ebay special(or maybe), but just wondering who has built turbo kits from scratch, as in piecing it out from company to company. I originally thought about purchasing Greddy's &HKS basic turbo kit but the cost is not logical at this time? think piecing it out is the route I want to go, hopefully by next spring. In my mind, buying piece by piece will be better for me than spending one lump sum on it. I highly doubt they are going to make a ultimate turbo kit for my car that i "Must have" in the year+ coming. So these are the parts I could think of. & if you could list anything I missed & what you have done. Are you happy with it, any regrets/big mistakes?

Turbo (most likely Turbonetics t3/to4e)
Manifold (full race)
wastegate
BOV (greddy)
Intercooler
Boost Controller
3" downpipe
Oil Supply & Drain Kit
Aluminum Intercooling Piping
Turbo Intake Filter
Gauges: EGT, Oil, & missing something else
Nuts,bolts,clamps
Management system (K-Pro)
***i'm still learning as much as I can about Turbo's & performance in general, so please don't hate to much***

Thanks in advance everyone