I bought one of the light boxes C&C were flogging years ago, similar to those Clarity dell. I didn't actually buy it from C&C though, can't remember who, but I contacted them a while ago as the batter no longer worked. They said they could supply me with a new battery, but it would require a spot of soldering. I thanked them for their very kind offer, but decided I could live without the battery as it works perfectly well via the electrics. I have two lamps that are battery powered, but they work much better when plugged into the leccy.
I use card somewhere between 150 to 220 GSM. Some stencils I post through my wee 'bug, but I still prefer doing it by hand, seem to get a better finish - sorry wee 'bug. :(
Roz