modelaratrod
You have a number choices which mostly depend on your ability to do the integration your self. I was in your position last summer with my TM2 table. I ended up converting it to dual stepper drive on the X axis with new motors in a configuration similar to a TM3 table. Open your driver box and make sure that the drivers are set to maximum output (mine weren't) as a first step. Also check your tables mechanical assembly, these tables require constant adjustment to keep them running true and tight. I kept the old driver box (same as your's) and used higher powered steppers so effectively had about 320 oz/in of holding power with the original driver box. You didn't mention which table configuration you have. If you have the TM2 configuration I highly recommend making the changes I did as a minimum. I can post photos if you want. I am not sure that any of the TM 8020 based tables will be ridged enough for serious router work. First replace your stepper motors with 4 stack ones to get more drive power on the X for plasma only and Y if trying to use a router. I used ones from Automation Technologies. For a turnkey upgrade buy a system from CandCNC, you won't need the ethercut option or their torch height control if you want to keep using the TM (Flashcut) software and box. The next choice in complexity is to buy a Geko 540 based stepper driver box and some new steppers and do the integration your self, this should increase available torque and speed by about 1.5 at a minimum.
John