I can't comment on Boxfords, but I'm aware they certainly used to refuse to deal with non-educational establishments, so information is scarce about them. However I have seen a couple comments lately where they appear to be a bit more open.

I had a Novamill. It was a sturdy machine for it's size, but work area was limited. Biggest limitation is the spindle clearance, especially if you run the Coventry Quickchange system. There are plans for a rise block on the Denfordata forum, which contains a lot of information.

If you get a fully working Novamill with a VRMilling licence key, I wouldn't personally be in much rush to upgrade, as VRMilling is pretty good software. The one I had happened to of been upgraded to the USB controller, and there would be limited gains to be made by changing.