http://www.plastidip.co.uk/
The GM stuff looks like conformal coating (a type of varnish).
http://cpc.farnell.com/electrolube/a...ing/dp/SA00362
If you go the conformal coating route I'd advise caution, it's designed to protect the PCBs and will insulate the pins in an rx if you don't mask them first! Spektrum already do this with their Rxs (as I'm sure others do)