I personally have had 0 issues raising hatchling ball pythons in 70 series tubs. I provide a warm and a cool spot hide and that is it. They have all thrived. If you want to get one rack to cover a ball python from neonate to adult I wouldn’t hesitate to use a 70 series. Just plan on utilizing hides.
I personally wouldn’t go with reptile basics, AP, boaphile plastics, or any of those. Why? Inferior tubs. Freedom Breeder and ARS make the best tubs with the nod going to Freedom Breeder. There are rack builders that offer the same style plastic racks with those optimal tubs. I’d go for the built in cup holders as well. I got a rack in a month or two ago from “Next Level Displays” that holds 16 of the freedom breeder 10 series baby tubs (good for ball pythons up to around 750g) and it’s great.
I’d recommend a 5 tub FB 40 stack. The thinner tubs are more space efficient (compared to a 70), will hold adult females up to 2500g or more possibly, and will help them feel more secure. But again, if you wanted to go with a 70 series I think you’d be fine with hides but that size tub really isn’t needed until you have very large females. I’d still utilize hides for smaller animals in 40 series tubs.
There was another new rack builder that Olympus Reptiles was sponsered by after TGR went out of business called “Pride of Texas Rack Systems” but when I just searched for their page was taken down. I’m assuming they already called it quits.
For stats I would go with herpstat. I have herpstats that have been running without a single issue since 2003. They’re continuously improving the design and are widespread well regarded within the hobby.