You need cheep? I twin turboed the 1uz in my land cruiser total cost $28. I was given two WRX turbos (a mate with a workshop) I cut and welded up headers at the last pipe from head, drilled a hole and welded a pipe in the middle of the headers and made a flange and welded it to pipe, bolted turbo on then made exhaust side out of bits of pipe i had around. made a two into one manifold making bends by cutting angled bits from straight pipe (all old exhaust pipe i had around) old oil lines found around work supply oil from oil pressure sender supply to turbos. brought 4 injectors and fuel rail on the net from 4 cylinder Toyota (same as 1uz) thats were the $28 went. drilled out top of inlet manifold and fitted the extra injectors (had to weld piece of aluminum to manifold to make it flat first) connected windscreen washer bottle to cold start injector and filled with water to make cheep water injection but could use a stronger pump(ECU turns it on over 8 psi), water hose connected where the heater used to go keeps turbos cool.
The exhaust manifold wont be the most efficient but with the power i have now i dont care, when i put the foot down the chassis twists and it lifts a front wheel. It did take a lot of thinking and a bit of work but it really did only cost me $28.
as for the first question on stock internals mine runs the standard WRX boost 14 psi i think.