any seedbanks I can walk into when I hit London in Aug?

Title says it all.

I did business with these guys by mail a few years back... Noticed they have a retail location, but have never been there...

http://londonseedcentre.co.uk/

i've heard they have a few places in soho that sell cannabis seeds awhile ago, but that's about all i know, and no clue on the quality / quantity of said seeds...

go to camden high street there are a ton of shops up there that sell a lot of different breeders.

You'll most likely have trouble finding any seedbanks, or shops with a huge range of stock. However, as o'er the above post, try Camden, there won't be a large selection of genetics compared to online, but yuoll find a good number of shops with seeds available.

If you're googling for shops, Google headshops, not seedbanks. Its typically headships that'll carry the seeds, but be warned, in Camden almost every other shop seems to be a head shop these days all selling the exact same merchandise.