Where can I celebrate my 30th birthday in London?

I'm looking to celebrate my 30th birthday on th 16th October with about 15- 20 friends, ideally I would like to go somewhere where we can have something to eat and has a dance area. I like somewhere glamours but not ridiculously expensive too. Music electo, r'n'b, house etc. A nice cly atmosphere and not full of drunk teenagers. Does anyone have any suggests? Thanks