What would you consider as a worthy replacement for a standoff ? As I asked earlier I was wondering if synthetic rubber (basically any insulator) could do the same job. Thanks for taking time to reply to my question, it is much appreciated.
Use some plastic sheet salvaged from packaging; something a little firm, about 0.5mm thick.
The motherboard will get slightly hot in use; keep this in mind when you select your insulation. My recommendation is to use motherboard mounting stand-offs because you need some space under the motherboard to allow for some air flow.
Look here for some ideas: http://www.fascomp.com/