Recommendations for knowledgable, well-stocked bike shops in/near London

[Sorry: the other thread with the same title has become locked for some reason and I can't work out how to delete it: https://www.lfgss.com/conversations/257896/#comment11931510]

Hello everyone.

I know shop questions are asked a lot but hopefully this one's sufficiently different to warrant yet another thread :)

I'm planning to splash out on a lot of accessories soon; everything from Exposure lights to a Garmin 810 to winter clothing to rollers to tires... pretty much everything that's not the bike itself. Between Wiggle and Chain Reaction I can get everything I need online but I'd like to
a) Support someone I can meet in person on a regular basis
b) Speak to someone who knows their shit
c) Negotiate a discount as it's quite a big spend
d) Buy as much as I can all in one place

Potentially buying a bike and getting a fit there would also be great, although I'm fairly convinced I should do this via Bespoke as they seem ace!

First port of call will be Sigma Sport as they seem pretty big/slick but are there any other recommendations?

Thank you!

In the other thread, by this point I'd had this reply from @freezing77

freezing77 in reply to @part_robot
I have always found Sigmas prices to be towards the top end of the
range especially on things like gps systems. If you can get a good
discount may be worthwhile.