The Davis is very nice, fairly upmarket, and girl friendly (at least it was Christmas/New Year 2006).
As for the distance from BTS, depends if you mind a bit of a walk. Davis to BTS is about 10 minutes. Far enough from the action to be nice and quiet, but close enough to not miss out :lol:
PS There are a few establishments between the Davis and Soi Cowboy/Nana.