The difference between MustGo Pro and PrepAir is PrepAir has an added fragrance odor counteractant component and MustGo does not.
What products to use?
MustGo is specifically targeted towards water related odors. PrepAir is targeted at a wider range of odor problems.
The only differences between Pro Packs and Consumer Packs is the Pro Packs contain 3 bars and the instructions are for Professional Use, while the Consumer Packs contain 2 bars and the instructions are for Consumer Use.