go for a stage 3 t3/to4e from turbonetics or another reliable manufacturer. avoid xspower and all that bulshit. t3/to4e's are pretty wallet friendly, and are easy to source, but the only let down is its wet floating bearings not roller bearing, and with your drag setup a quick spooling turbo would be alot more efficient, e.g a GT35 or 35/40r.
with the ecu, ive heard all good things about the megasquirt. Other options include the link V5, im using one and has had very good results tunability wise, and also there is alot of link knowledge out there within the dyno tuning community! Give kelford cams a call about your head, one of their employess has an insane 4agte mr2, and just down the road at NZEFI a guy there has a 310 hp atw ae86 4agte, using the standard 16v head and standard bottom end, doing 11 seconds on the strip!! its all in the tuning
