I think it's an ace idea, Andy. Re dates I think you might be being a bit ambitious wanting to have it in 2 weeks, but see what people say.
I had been thinking myself about starting a thread trying to arrange a get-together, but miles in advance. There are lots of people on here that I've never met that I'd like to. Personally I could do with having 3 or 4 months notice as it would help with travel costs, etc. I feel like if we get a date in the calendar quite far ahead and keep on bumping the thread then we could hopefully get the maximum amount of people there, rather than just a handful. Anything short-notice and I immediately think "No".