AMP supports NT licenses only in the grandfather clause from 2014, when they discontinued their partnership. If you have a NT lifetime license, you can just get an NT connection and broker service as a package for free IIRC. Because you already paid your lifetime dues. So you just pay the typical exchange and commies. The rest is free forever. Like historical data and upgrades. Etc etc.
AMP will offer you CQG which is about as good as any retail trader would need. It is direct from the exchange so don't worry about quality (unless you're a psycho HFT). Also, read ON's post carefully...I am also grandfathered in with NT.