The London Lounge

as in http://www.beautiesltd.com
A lot of "comedy", but some items may strike the right note for you.
They can also turn a regular tie (if you can bear parting with it) into a bow tie.
Granted, not "in London", but accessible from your nearest computer.

I wear bow ties at work. As a surgeon, it doesn't flop onto the patient (or wound) as I do an examination. Secondly, I have ruined many a tie when taking off talcum lined gloves and repositioning a regular necktie. It does give one a slightly affected "intellectual" air, which can paradoxically comf...