Re: tell me something about this cabinet...
I've always preferred the look of buying the matching cabinet for your head. The 1960A has GT-75's, which have a lot of bass and treble and a real grindy tone. They sound good, and are appropriate for most modern Marshalls, although I prefer the 1960AV, which has Vintage 30's and a more growly midrange bark.
For your amp, I'd hold out till I found a used Mesa Rec Cabinet with whatever speakers they put in them. IMO it'll just look better, and also give the true sound your amp was designed for. Roughly, 1/3 of your tone is the cabinet you're using, so stay with Mesa, if you have a Mesa head. There are so many used Marshall and Mesa cabs, that you don't need to jump on the first one that comes along. Wait for the Mesa cab.