regarding the venue i think it is a case of if you think it is ok go for it:-)
the hard bit would be what day,just a idea if it is a problem spin a coin that sorts a lot of problems.
just my opinion say you are having a get together at/on a certain day all welcome meals available on the night.
Email Mike Boydell at AM, he may be able to help out with suggestions for a speaker or two, and I'm sure he'll be pleased to give you some ideas on organising such an evening.
I live in Dorset, so too far for me, but good luck!