Unfortunatly the S13 box wont fit the SR20DET engine, so the one in Neppys is no good
All SR20 Boxes are basically the same, though there may be differences in the sensors on the JDM cars - these are all bolt on parts though
I should have a spare one when I get the car back next week, has a slight whine, but wont cause any problems, £100 if you still need it....