This Londonesque enough?http://www.condorcycles.com/2011-Range/10504-Paris-Frameset-by-Condor-Cycles/flypage.tpl.html
http://www.evanscycles.com/products/charge/plug-2012-single-speed-road-bike-ec029988I have an older version of this! Its pretty nice. I would get super narrow flats (bars) so you can fit through traffic! Defo helps in busy city's!Have fun.
Don't listen to anyone who says you need narrow bars, especially people who have only lived in the Lake district and W Yorkshire