So I have a to4b v trim stage 2 with a .48 exhaust housing.
Its apparently a t3/t4 hybrid, its just that turbo n00bs seem to be JUST talking about the compressors nowadays.
You will be able to run 13's with a decent car, my friend spent $600 on some janky used turbo kit, and ran 14.3 with an otherwise fully stock 93 EX (chassis, suspension, engine, steelies).
I would highly suggest building the bottom end BEFORE the head. A broken rod is far worse than a weak cam. A stock z6 im/cam/head can do >400whp anyways, proven by facts the prove it.
Boost your stock block, LEAVE it stock, and put pistons/rods into the other. You can always do head work later. Its all of $30 for OEM head & intake gaskets.