The 82-83 turbo distributor will work. The 81 cas will work with some modification such as grinding every 2 out of three teeth, and using a hall effect sensor. http://forums.hybridz.org/index.php/topic/77233-30-1-tooth-wheel-with-cherry-hall-effect-sensor/
Sounds like you've might have found your problem. "I installed the slave cylinder I needed to press the rod quite deep into the slave cylinder in order to make it fit the fork... "
A lot of new turbos at that price are Chinese turbos and the quality can vary extremely. There are plenty of manufacturers (Holset,Garrett,Precision,ect...) to choose from. You know what they say "You get what you pay for".