Hi Ross,

 

There are many, many Legacies flying without P-static problems disabling their avionics.  Before I went to a lot of trouble electrically bonding parts of the airframe, I'd try to determine how your Legacy is different from the others.  And I'd make sure all the electrical grounds are solidly connected. 

 

Do you have any indication that P-static is a frequent problem in your airplane?  Is anything except the GPS function of your MGL Voyager affected?  I once picked up enough static charge that what little hair I have on my head stood straight up, towards the charged canopy.  It didn't cause a problem with any of the avionics, though.

 

Dennis