Zoom is alright but I prefer Spec clutches. I run a Stage 1 (rated at 480ft/lbs) in my daily driver and it is cheap. Just a hair more than the stage 1 Zoom you mentioned but still less than the Zoom stage 2.
They (Spec) have incredible clamping force and holding power yet the pedal effort is not much more than a stock OEM clutch. I swear by them.
As for changing one out in a '94
stang, pretty simple really. Before you remove anything, grab a grease pencil and mark both the driveshaft and the mating flange at the rear pinion that way when you go back together with it, you need to line up the marks to ensure you've re-installed the driveshaft properly clocked to avoid any vibrations.
You don't have to follow my steps exactly but everything I mention will need to be done in whatever order suits you....
Disconnect the battery, remove the driveshaft and exhaust and I usually take the cross member out at this point and leave my floor jack to hold it(
tranny) in place. Next remove the console, shift boot and shifter handle and then the starter. On the transmission, there are 4 bolts holding it to the bell housing. It is possible to remove the T5 from the bell and leave it in place but since you are changing a clutch, might as well take it all. There are 6 bolts holding the bell housing the block. Once you've got the
tranny and bell out, take the pressure plate bolts out. Leave the last one inplace on the bottom until you have a free hand to catch the disc. They hurt like heck when they drop unexpectedly and land on your big toe (don't ask
). Remove the last bolt and pull the pressure plate and disc out of the way. Since you're here, you really should change both the throw out bearing AND the pilot bearing in the back of the crank. You also need to get the flywheel resurfaced to clean it up. Any good machine shop can do this for you. Be sure to keep the new disc clean of grease marks as well as the newly re-surfaced flywheel. MAKE CERTAIN you use new pressure plate bolts and flywheel bolts. Once they have been torqued, the threads stretch and they are not as strong as they were brand new. Use the alignment tool to line up the disc to the new pilot bearing and tighten and torque the pressure plate bolts in a star pattern. DO NOT FULLY TORQUE EACH BOLT ONE AT A TIME, do them in sequence. I always tighten them by hand, then go back and snug each up using a ratchet and then when torqueing them, torque each one half of the full torque amount, then go back and torque them complete to specification. Most flywheels are torqued to 65ft/lbs and the pressure plate are usually in the 35ft/lb range. So when doing the flywheel/pressure plate, do a first torque sequence to about 33ft/lbs, then (after you've torqued all 6 to 33ft/lbs) go and torque them to the other 33ft/lbs. It would be smart to check manufacturer torque ratings as not all flywheel and clutch combos are the same. Hopefully, you get the idea.
Keep in mind, this is obviously just a cliff notes version and a Chiltons or Haynes manual will be your best friend for this job.
After it is together and you need to adjust the clutch, set the throw out bearing to between 1/8" abnd 1/4" gap between the face of the bearing and the fingers of the pressure plate with the clutch pedal all the way out at the rest position.
Richard
Tech Support
Tremec TKO, T45 & T56 Transmission Systems
Help Choosing a Good Clutch And Advice On Tranny Pull. 
