Ground wiring question.

[MajorHavoc]

I'm looking at putting together a Supercade type cab.

Finances dictate a four player I-pac.  This being the case, It will be necessary to share inputs between the upper and lower consoles.  Would it be possible to run separate ground wire daisy chains for upper and lower consoles tying them together at a SPDT switch which would feed the ground terminal of the interface?  The switch would select which set of controls would be active.  Is this an inexpensive solution or simply another electronics to smoke converter?

TIA
MIke