Marshall JVM should do what you want and is fairly readily available on Ebay. Four channels should cover what you want. I looked at it closely myself but in the end went for the H&K Switchblade instead and I have no regrets. Endless possibilities in a very compact format and some great tones in there, though I agree that with this sort of amp, you're never going to like everything. I find I use the clean channel quite a bit, the crunch channel sparingly, the lead channel a lot and the ultra channel very little. The thing is, there's so much variety in it that there's something for most people and in a covers band it's perfect. I was overly concerned at first by purists saying it wasn't a 'real' valve amp as the channels were 'voiced' similar to other famous amps but eventually I concluded that if it has valves in the preamp, valves in the power amp, behaves like a valve amp and most importantly, sounds like a valve amp, then it probably is a valve amp. Of course, these aren't so readily available used but I'd certainly look at a Marshall JVM as it has loads of variety, will do everything you want, you can get them second hand and there's a lot of respected guitarists ranging from Joe Satriani to Synyster Gates using them so it can't be that bad. If they'd done a 4 channel 50w combo I'd have had one for sure.
