Your choice of machine for Students is a great one. I think the Tormach is an excellent machine for this. Your Inventor and Mastercam would be great also. You will need to talk to Mastercam or Tormach to see if either have the post-processor file that will convert the mastercam imports to g-code the Mach-3 sofware (the Tormach uses Mach-3 to run the code) can run. The Mach-3 (Artsoft) folks may have something too. I bought the large tool set with my machine and have added to it since. I bought the 4th axis with my machine and I have used it quite a bit. It will also provide an additional training tool for learning G-Code for your students. The Deluxe stand with the coolant system is also a great addition. The Vise I used is from my bridgeport. A 5" kurt clone. It works great in the center slot of the table. I got it on E-bay (new). You will not go wrong with the tomach. Some of your students may also go on to start their own businesses beginning with the tormach.
Good Luck with your budget. I hope you can get everything you want. It is worth it!