I feel your pain. I researched the crap out of slave cylinders until I came up with this set up. I have a 351W with a T5 and used this set up from Autoworks Racing.
http://www.autoworksracing.com/hydra...ts%20enter.htm
I attempted to attach an image but am not sure it I did it right but you will see one on the website.
Anyway, these guys were real helpful and can help match you up with the correct part for your bell housing or transmission.
Good luck,
Richard