Thank you all for feedback- we are currently sounding out venues but in my dreams it would be at Union Chapel because it's acoustics are just MMMM!
If it were to be there, charity-wise we'd like to help out their support for homeless people, but budget projections suggest we may well be able to "pet" a couple of worthy causes. I'd also be very interesting in helping out non-gov funded charities, as the government has seemed so intent on wiping out the spirit of live music. nb: that's me speaking, not this "event".
I'm hoping it will be more than just Islington foggy types who turn up, this is why i'd make it on a weekend and with decent finishing times so allowing for people to make it home from the region. I have no great "bringing folk to the ignorant masses" rubbish in my head, I'd just like a winter event in the city that's my home! As I say, it's a project for this month, so thanks for the tip P from E, and Dave B, when I have compiled an info dossier I will endeavour to contact folk clubs so that they can get involved too.