London (or nearby) Baby Naming venues?

[LeahE]

We're looking at having a baby naming ceremony sometime this summer and would like to find a suitable venue -- preferably somewhere with an inside space (preparing for typical British summer) but also an outside space in case we manage to hit a sunny day. Likely to be for about 30 people, I would guess.

Does anyone have any suggestions for somewhere suitable that can be hired, reasonably accessible from SW London?