GT25R is what I have on James K11. Superb turbos. Should spool up very fast on his and make a huge fat chunk of torque! 
Ultimate would easily run with SR20 throttlebody, and you would need the greddy map sensor. FYI for me to supply the whole lot (EMU + Loom + MAP sensor) is £620 to have it fitted is £200 and to map is 25hr.
Blue e-manage would do the job as well, but may not cope with larger injectors as well - but thats a limitation of your stock ecu - NOT the blue e-manage, however it would require much less mapping than the EMU.
