Those B&W were good speakers in their day. 15 years ago. The cones probably need replacing by now anyway.
Things have moved on since then so you can certainly get something smaller and better sounding today for a reasonable sum.
B&W make good flat and accurate speakers which could be classed as monitors at a pinch.
So try and avoid the cheapest so called active monitors like the KRK Rockit range because they are more coloured (or 'voiced' as the marketing people like to say).
Magnets have got stronger, amplifiers smaller, cooler and more powerfu. So you could get the same SPL and frequency range from a contempory 5" cone as you get from the 7" B&W. Active crossovers are better than passive and tweeters, especially ribbon tweeters are now a bit cleaner and less shrill.
I'd go for a pair of ADAM A5X if you afford them (600 Euro). F5 if that's a bit steep (400 Euro and comparable to what you spent on the B&W new. so the 4 amps are effectively free).
The JBL 305, Mackie MR5 and Yamaha HS5 are all cheaper still.
Also look for Event 20/20, Equator D5 or maybe if you are mainly into house and pop music the KRK VXT 6.
The ADAMs are where it's at though. I just feel the need to offer alternatives so as to avoid looking biased. Best price/performance on the market. 5 year guarantee too. Try getting that out of M-Audio.