Where can I meet single Girls into Metal or Goth in London???

Answer 1

1. Here are some clubs:

a) The Underworld, Camden Town
http://www.theunderworldcamden.co.uk/
b) Slimelight (Saturdays, at Electrowerkz), Islington
http://www.electrowerkz.co.uk/
c) Sin City (Fridays at Electric Ballroom), Camden Town
[previously the popular Full Tilt]
http://www.electric-ballroom.co.uk/club_nights/index.html

2. Have a look at this (individual's) website. It seems not to have been updated for a few months, but nevertheless a great directory for London Goths - including places to buy clothes, recommended pre-club pubs, and hang-out locations.
http://www.the-dreaming.demon.co.uk/london-guide.htm

I hope this is useful.