Dosent matter what manifold that turbo would not suit a rb20, mine is on the limit size wise and is only the smallest type to4e, it makes fullboost at 4300rpm so yours would be 5000+, not good with little of boost.
Also the turbo would be a tight fit in the engine bay bolted to the stock manifold, so check that as well.
What other mods has he done to the car, in a few months i will be selling my kit, trbo, manifold, wastegate, cooler, pipes, chipped computer, z32 afm, everything to get 230rwkw and 12sec qtr times, for a lot less than would cost to do new.