Excellent idea! You might also consider adding this list to the community – created wiki, and that way other people can add to it. Just put it in the “devices category” under “light switches (UK)” or something similar.
http://thingsthataresmart.wiki/index.php?title=Category:Unofficially_supported_devices
BTW, any zwave or zwave plus certified single gang switch on the UK frequency should work for basic on/off/dimming with SmartThings. It won’t require custom code for basic features, although it will likely require a neutral wire at the Switchbox. Vesternet always has some of these. (The dual gang switches may require custom code.)
https://products.z-wavealliance.org
Also, one of the most popular solutions for UK homes doesn’t use all in one switches. Instead people use one of the in wall micros from Fibaro, Aeotec, or other brands which can be placed in wall and then used with any regular switch.
The FAQ for UK lighting covers all of these general options ( although without giving specific brands and models) and more and might also be of interest.