Cheaper option - buy a gts-t.
Got money to spend? Then buy an rb25det, 5 stud brake upgrade, everything you will need engine wise (turbo, ecu, manifold, etc.), then get someone to fit it.
But the short answer to your question, no advantage of rb30 plenum, dunno why youd want an rb30 loom. Turbo means youd need to prepare your current engine for it, or see my second point.