T3 or T4 flanged turbo. Read up on compressor maps and pick a turbo that suits how much boost you want to run and when power comes on.
Exhaust manifolds & dump pipe
Intercooler and piping
Wastegate
Oil sender T-peice and sump drain for the turbo oil feed & lines (sump will need to be removed and a hose piece welded on)
Haltech piggy back for the delco as hardly anyone tunes delco anymore + dyno tune
Fuel pump
fuel pressure regulator
Injectors
electronic boost controller
bov
boost gauge
turbo beanie & heat wrapping
battery relocation
I would keep aside $10,000 if you cant do the work yourself, you won't use it all, but that is a realistic budget considering all the costs involved in having it perform properly, and give the power safely. I have read guys spending 2 -3g doing the work themselves, but the end result is a problematic setup full of heat issues, smoking turbos, boost spikes and leaking head gaskets.