I thought, you have already tested, if the enc box is compatible.

At the moment, I'll better try to get the machine running with a Mesa 7i76e that I have already here. That board have all in it what I can do with IP/M + enc + mpg + additional IO.
It have as standard 5 S/D, 1 analog out, 1Encoder in, 32 DI, 16DO and from the DI, I can use 2 ports for a Mpg and another 2ports for analog in for feed or speed rheostat. Additionally I can add 2 other boards with similiar capabilities and to all this boards each a easier Board with additional IOs

But for a further Project, it seems good to use a board, that don't have more in it, than what is needed.
Mach3 as well seems a lot easier than Lcnc but is payware.