The vipecs are a great unit from what I've read I'm running a link G4 which is basically the same thing and my car runs better than it ever did with a nistune ecu. A fresh 30/25 should piss 250kw in safely! Just depends on the tune! I'm smashing 25psi boost down my stock 25's neck and making 336kw at the wheels and have done safely for the last near 2 years now. If you are only chasing 250kw just go for a hypergear or gcg highflow turbo as they are cheap,reliable and proven performers. Personally I don't think the kind of Ecu u run is Gunna affect emmissions it all boils down to your exhaust and tune Steer clear of ebay junk turbos as they are generally laggy and unreliable for the extra $$$ use a tried true performer that ain't Gunna risk ya freshly built motor. Just my 2c anyway