Rotel RA-04 should be on your audition list, it RRP's at £250 though so for a little more moolah you might want to try out the Audiolab 8000S which is about £400. Another option might be the Arcam A70 which I found a good deal on here: http://www.weymouthhifi.co.uk/website/arcam/arcam-a70.htm If you're gonna spend this much money on an amp though, I'd consider putting a bit more beef into your speaker choice. Perhaps looking at the silver series from MA instead of the BR1's.
cambridge audio azur640A, Nad c352 ( can be got on line for about £300), rotel RA 05, Don't touch the Arcam A70 unless you like a soft sound lacking in punch and drive. Just my tuppence worth but i thought it was awful.One of worst amps i have heard and considerably overpriced. i don't say that lightly.The nad and the cambridge both give a more dynamic exciting listen at around half the price.
I agree with Fraziel - The Arcam A70 is gutless so i'd leave well alone, especially if you're looking to partner with B&W 685's!
With regards to an amp for less than £300 - Take a look at Ebay. If youre fine with 2nd hand amps (obviously make sure theyre in mint condition and form a truster seller) then take a look at the Arcam Alpha range (Arcam 8 or 9 integrated amps) or there are some cracking Musical Fidelity amps going currently. There is a MF X-A1 amp thats on there. Superb amp and will go very well with the B&W's.
As above, take a look at the NAD amps as well, new or used on Ebay (Superfi.co.uk) have some good deals on NAD amps currently. The NAD C352 is at a good price. There are one or two decent NAD amps on Ebay also.
If you do look at Ebay and see seperates that youre interested in, make sure the seller is genuine. Also, ask him some questions and see if you can get more pictures as if theyre a hi-fi fanatic then they will be more than happy to supply you with all info requested.
The C320BEE is a cracking amp and would save you some £££. Means that if you get the B&W 685's then you can purchase soem decent speakers stands to go with them. Make sure thayre mass loadable though as this really improves the sound quality!
am selling a set of 51 cm custom design RS 302's with the glass base for £80 quid. RRP£140 and immaculate.Just thought i would add that in! The c352 is a cracking amp and could possibly be purchased on the cheap.Seen a few deals on line. i would also listen to mon audio RS1's.they go well with nad stuff and are a good bit better than the bronze 2's.