Someone on the Yahoo group posted they were getting this unit:
And were looking for a mount.
I suggested they use this:
I have a Zumo 550...an "expensive" unit, and have no problems using RAM mounts. The ones on ebay sound like knock-offs and I doubt I would trust them.
Mine uses a RAM ball that I bolted to the mirror stem mount and does not move.
Do note that the Zumo was built for motorcycles, and most other units are built for cars. Hence, the unit above is likely not waterproof, and that is why I suggested using the Aqua box.
The others on the market meant for cars can use the same mount if they fit.
Bulldog found a fairly inexpensive GPS that seems to work well, you might want to do a search for it.