The SVT trans and non SVT trans are the same.
There are many upgrades available for that trans. If you are buying a wrecking yard trans, it is usually best to find the newest one you can. Since they continued building Cougars for two more years don't forget looking at them as well. The biggest factory revision came early in the 2000 model year so the best wrecing yard trans would be a 2001 or 2002 Cougar.
You really should read through the trans forum posts, especially the pin up posts.
The only really weak point on the MTX75 is the final drive spyder gears. The best upgrade to strengthen this is to install either a Torsen or Quaffe limit slip unit.
Do a little homework on the trans forum and you can learn all you need to know and then some.