Stirring the pot... Mechanical vs. Hydraulic clutch?

Just an opinion, but for what your doing, go with the stock mechanical linkage. Do yourself a favor and reinforce the fender apron where the outside pivot stud goes and consider a torque strap on the engine. The stock linkage can have issues and bind if the engine moves around too much. If you put a diaphragm clutch plate in there, don't install the over-center spring.