He only wants 300rwhp...A rom tune with an SAFC to fine tune it would be fine for him honestly. I never said anything about the full race set-up being the cure to all problems he could have, but it would elminate some of the issues some idiots have with running shitty manifolds, wastegates, ext...boost creep kills motors. But you are correct with tuning being the most important thing, but that comes with any motor period...
Hell he could just do an s15 t28 with s15 480cc injectors with an SAFC tune... to make 300 hp if he wanted too and easily at that...