Shopping for a RTW suit in London (under ~1300 pounds)

[max2013]

I live in California but visiting London now. I was thinking to buy a RTW suit up to ~$2000 (1300 pounds or so). My problem is that I don't really know how to tell a good fit. Is there any store where I can trust the sales people? And do you have any particular brand recommendations? Unfortunately, I'm limited to central London this time.

I'm looking for a slimmer fit; in case it matters, my sizes are: Neck 14 1/2, Sleeve 33, Chest 36, Overarm 44, Waist 32, Hip 37, Out seam 38.

If you suggest I shop in California instead, that's fine too.

Thanks!

 

[RogerC]

Richard James on Savile Row.