Having a small workshop, I did not unfortunately have space for anything bigger than a 12x30. Oddly toyed with the idea of a 12x48 using the extension kit but that maybe a future project. Being a newbie to a CNC I thought it would be useful put some details down on my set up.
I started with a pretty conventional 24" deep work bench, cleaned it up and unscrewed the top. Length was around 62" long
Removed the top and installed a 28 x 49 x 3.5 " torsion box out of one sheet of 49 x 97" 3/4" MDF. Not sure on the odd sheet size at HD? The torsion box was made from 2" strips, 2 length ways and 5 the other, dado’s cut, glued and nailed. The extra bit left over from the sheet extended the top to give a nice desk for the electronics.
Last step but one was I added a 24x48" sheet of 3/4" MDF to the top, then cut out the centre portion to be the spoil board with the y gantries sitting on platforms so I did not lose any cut height. A small section of MDF was also latter installed to cover the electronics behind the monitor to limit dust ingress and also provide a monitor shelf giving more keyboard room.
This made for a very stiff table, and worked really well for a smaller install.