yeah, that’s kinda similar to what I’m building right now, but mine evolved quite far of the original MPCNC.
It’s totally doable with a regular MPCNC, though, to be honest with you, the MPCNC prints really fine as it is. On my previous machine I was printing with a gigantic 50cm long Z axis and got really great results, so I suggest you to not burn the steps, try the standard machine first, and then maybe, upgrade if you feel that it’s necessary.