They don't use the .0 indication anymore.
I see links to both kits,
MM2 and
MM3, both feature some options, include a hopper, baseboard, and free shipping.
The difference is the MM3 has 3 rollers, the MM2 has 2. The 3 roller systems allow for a different kind of crush, with less husk shredding.
The Pro series feature 2" rollers instead of 1.5" (non-Pro), and hardened rollers options as well as different shafts (3 flats or keyed).
The PD series are for
Pulley
Drive systems.
The SL has helical
SLotted rollers.
Last but not least, you really should consider (semi-permanently) mounting that HF drill I mentioned before, for it is heavy, has a lot of torque, and could cause injuries and damage if the rollers lock up. I speak from experience.