wah... 300-350 bhp on wheels ar?? Ummm... hmm... this one ar... need to plan as u go wan...
TD05 i think won't be able to produce that high HP... so the turbo has definitely have to make way for a bigger one... perhaps a TD06 + external wastegate... then of course an engine management, bigger fuel pump and a fuel regulator. If u have the budget, get a standalone. Do pnp, full engine balancing... i think u should be able to push with that setup up to 350hp at the wheels.
I know a couple of guys who managed to push up to 300hp on wheels with the TD05... but they're on EVO3 la... which btw has a higher compression than the evo1 and higher cam lifts... and not to mention a slightly bigger turbo fin.