Having researched what is available I think I am going to use Domoticz as my HA platform running on a Ubuntu virtual machine. I was going to use a raspberry PI with either a USB stick or the Razberry for the Z-wave interface with a Domoticz instance on the PI acting as a slave to the main Domoticz instance. I need to have a remote z-wave device as the main server is not in a good place for wireless comms.

What I concerned about is wearing out the flash card on the PI with the constant logging from Domoticz. Does anyone have any experience or suggestions on how to reduce the number or read / writes etc.

Along side z-wave I will be needing Lightwave (RFXcom?) and using the API to connect to Evohome. Domoticz has an plug-in which works very well, but I haven't found any other Evohome integrations.