You can get T28's from 200sx's S13/s14/s14a/s15's if that helps.
You can also get a brand new gt28r (ball bearing) which can give about 330 max bhp for around £550 if you look around in the UK. If you buy an s15 dual ball bearing turbo from Australia, it may be even cheaper
(compared to £900+ that K-tec/bb want for a t28). If it is the gt28rs then it will be closer to £800+ from other vendors. but do not buy fake ones off ebay from buyers such as XS power.
You will also have to uprate your gearbox (or at least it is sensible) to cope with the additional torque, which will cost a bit extra.
Matthew