Need to know you power goal or intended usage before making suggestions.
zas, either a high flow or t28 based turbo is going to be limited to 250-260 rwkw anyway. For more than that a gt30 sized turbo is needed and they start about 1700 new.
On top of the 28 based turbo price you would need lines, adapters and possibly a revised dump so the price goes up.
Best bang for buck would be a slide highflow, best bolt on option would be a gcg highflow (this is my opinion based on running a gcg highflow followed by a similar sized non bb turbo on the same engine. The transient response difference is huge at small to mid throttle openings even though full boost hits about the same time), for more than 260 start looking at 3071's and 3076's for 300 plus