I can tell you the integrated's that I was looking at, but my speakers were not as power hungry as the bw. Someone just posted a used Rotel for $425, The audio refinement complete (60w per channel but very nice and musical sounding), The roksan caspian..I have seen these go used for $595 sometimes, the creek, nad, arcam. Someone more familiar with the power requirements of the BW can direct you to the type of wattage you want. If it were me, I would sell the AP Oval 9 speaker cables to spend more money towards the amp (you should be able to get what you paid for them if you bought them used off audiogon). As never owning these but from what I have read they are more towards the neutral to bright sound, the opposite I would think of what you would need for this level of equipment. You should look to spend around $30-50 used on interconnects (straightwire chorus, MIT T2, DIY cables, audioquest)and less than $100 used on speaker cables (a little more for bi-wire versions)I would go for a warmer sounding cable but that is what I like. For $600 you could get a Adcom GF710 pre-amp (remote) and a adcom 545 or 5400 amp. I would advise you to do more research (search older threads,look on audio asylum also) on integrated and pre/amp combos or what amp's people are using with the bw and then post again. There are also some good deals in higher wattage amps if you go something a little older.
Patrick
Patrick