Chris,
Contact Circle BMW..they have a website to purchase the shaft and knob separately if you want to replace the T-handle. When I did the conversion a couple of years ago, I purchased a complete late model E-36 shifter assembly and then using an arbor press, pressed the respective wrist pins out of each base and swapped the E-36 shaft into the E-32 base. The two bases are different in terms of the direction of the cable feed. The archives on this board may contain the actual part numbers but Circle BMW should be able to hook you up. Believe Bavarian Autosport has a large selection of different late model pistol grips...check out their on-line catalog. I toyed with the idea of having a composite leather and aluminum pistol grip but went with an all leather grip because my car interior has virtually no aluminum...just the top strips along the door panels.
HTH,
George