I doubt you could get an insulating section of pipe installed before the meter without splashing the cash at your gas network operator, but could you get a gas fitter to install an insulating piece of pipe straight after your meter? Then your earth bond would go to the pipework system after the insulated piece (before the first tee) and be at the potential of your earth rods rather than any potential current flowing from next door.
(I'm not sure how the DNO/electricians would view conversion to TT - worth asking around. At the very least you'd need RCDs on everything)
Theo