K8200 Large Print Area Mod

Hi,

I have a K8200 that I purchased a few years ago and would like to upgrade the size of the print area without increasing the foot print. My idea is to replace the cross arm that carries the extruder with a V Slot extrusion and mount the extruder on a moving carraige with an additional motor. This should enable the area to increase as the x-axis will remain as is. The idea is to beable to move the bed in the oppiste direction to the extruder.

Will this work?
How to connect and control the cross arm carriage motor?
How would I accommodate this in Marlin?

Your comments and assistance would be greatly appriciated.

Regards