Anywhere easier to get to? I used to go to the big Aveda salon in Covent Garden, but stopped because it was pointlessly expensive, and I got messed around loads with rearranged appointments and rarely saw the same hairdresser twice.
I've been going to Willie Smarts in Clapham Common for the last 7 years now and would really recommend it, it's a bit scruffy round the edges, but the colourists and cuts are good. They have a branch in Crystal Palace as well, but I've not been there.
I've had both Aveda and normal highlights - I think Aveda include lots of extra plant extracts - but to lighten your hair you need serious chemicals, Aveda or not. I always found my highlights were always more reddish with Aveda (I'm mid brown) but when I switched to Toni & Guy (they use L'Oreal I think) I got the caramel blonde tone I wanted.