That is correct. There are all in one solutions like the G540 gecko drive that does the same thing as the TB6560 but the price is $250ish so buying individual drives works out cheaper. Hence I suggested you keep the TB for the time being. The TB's are cheap and manufactured as such and they will have their issues but for the price there is nothing else unless you go with drivers like the ones that 3D printers use and cost £5-£10 a pop. They do however go pop very often too.

From what I understand you have made your mind up on moving away from the parallel port. So the next step is to identify what you budget after the purchase of a motion controller is.