You have to get a business license, which is usually pretty cheap depending on where you live. Then take the RTI training certification course. Get setup with RTI as a dealer. Then you can get all the hardware and software you want.

Unfortunately in this day and age of "Anti-Right to Repair" and "You Own Nothing" culture, any other control system you want to go to is going to be the exact same thing. Even worse, because a lot of the other ones will cut you off as a dealer if you don't do so much $$$ with them each quarter/yearly.

Good luck.