Hydrofarm thermostats are fine and will get you by, I have several, but personally I prefer a proportional thermostat like this one http://www.reptilebasics.com/ve-200 They're more expensive but I think better quality.
In 15 years of breeding ball pythons through several generations and having produced over 1000 hatchlings, not once have I ever used any kind of suppliment for my snakes. I do not believe that it's necessary to suppliment when you feed whole prey items like rodents.
The majority of the hatchlings that I have produced were started off on live hopper mice, then adult mice (live or frozen depending on the individual) then switched to small rats when they were of a sufficient size. While it does happen that certain individuals can become fixated on a certain prey type, it's actually pretty rare in my experience. For those few individuals that refuse rats, I just feed them mice. They are perfectly healthy and trive on an all mouse diet as long as quantities by weight are sufficient. As was said before. 'Feed them what they're willing to eat'