All the testing we have done is with the Z-Stick: http://www.amazon.com/Aeon-Labs-DSA02203-ZWUS-Z-Wave-Z-Stick/dp/B003MWQ30E
We use the Open-ZWave library so any gateway it support should work. http://www.openzwave.com/
I'll be posting some how to articles shortly. The main thing is that you need to manually insall the drivers for the Z-Stick. The Z-wave module is not included in the main download but you can get it and manually install it in Mango here: http://store.infiniteautomation.com/module/zwave
Thanks,
Joel.