Check out Ireland engineering or VAC motorsports for your performance/racing internal components.
pelican parts for all your gaskets and anything else oem or quality aftermarket.
Im a big fan of garrett turbos and youd be ok with a gt30r .82A/R or even a gt35r .63A/R. the gt35 may be a bit big for your 2.5 but if you use the .63A/R housing that will help it spool before redline