Automatics are an answer to a question few were asking. They have their place, but the American love affair with automatics annoys me. If it were me, I'd stick with the NSG - the rebuilt ones reputedly don't have the problems we're all familiar with - and - despite its 1st gear not being low enough, its lower than the others mentioned. With that said, the NVG3550 has a lower 1st than the much vaunted AX15 - for whatever that's worth.
If I need to rebuild mine, I am going to pursue the possibility the so-called "wide ratio" version - if I can find anyone who has the parts and knowledge which may be impossible as the thing is apparently unicorn tears.
Evidently you can retrofit the front half of a TJ NSG370 to the back half of a JK NSG370. Just costs a lot of money.