Was going to say put in a ground stake close to the obs but if the OPs power system is MEN (with single point earth neutral) then really this is not a good option.
Antistatic gear is available from RS & element14 or fleabay.
Still think multiple SMPSs are capable of causing potential differences between faux grounds but yes Gary is right if your moving around and then getting discharges ESD protection or minimisation will be on your agenda.
Simple things like ESD grounding mats (correctly grounded thru bleeder resistors) types of clothing, flooring etc. Funny enough we measured the military DPCU's and found them the lowest ESD generating clothing around! Even better than our clean-room smocks, clothing & shoes.
