Behringer has just launched some new 1u lightweight amps. The EPQ1000 looks perfect (2 x 500 watts, 10" deep, 5kg) at an RRP of £240. There are no independent tests yet, but these could well provide a killer bass amp with a suitable pre. Bridgeable, balanced input (XLR or jack), unbalanced input, limiters, built-in crossover - well worth checking out when they arrive in the shops. The usual UK retailers are advertising them already, although I doubt they have any stock, as Thomann isn't even listing them yet.
[url="http://www.behringer.de/EN/Products/EPQ1000.aspx"]http://www.behringer.de/EN/Products/EPQ1000.aspx[/url]