I'm looking for suggestions for a four-gang dimming lightswitch or high-powered two-gang.

I currently have a four-gang lightwaveRF dimming lightswitch in my kitchen. Each switch controls between 4 and 6 ceiling downlighters, with 35W halogen bulbs in. In the recent hot weather, the lightswitch has stopped working, probably due to over-heating. This is the 3rd replacement lightwaveRF switch that I've had (the other two went during hot weather as well!), so I'm now looking for alternatives.

I have other z-wave devices in my house, so would be happy to go with that for the switch. From a fairly extensive search, I couldn't find any four-gang z-wave switches, so one possibility would be to combine the four circuits down to two, which would require switches that could handle around 315W (only ~1.5A - doesn't seem excessive?). However, it would be good if the new switch could fit the current double-width patress box, to save having to do any patching up.

Many thanks for any suggestions...