i've decided i quite like 1x12s recently ;)
you could also try a weber beam-blocker to diffuse the sound a bit in a live situation. if you're going to order from weber, you could also look at his speakers.
i think you should look at the speaker first, and then the valves. you could get a used speaker on ebay, then you won't have to break it in, and you can sell it on without losing money. i also find the v30 harsh - but not harsh in the way of painful sounding - harsh in the way of its hi-fi character, and peaky EQ curve. its actually sounds quite good recorded i think, but in a room i'm definately not keen.
i've only tried 4 speakers in a 1x12, and they're all celestions:
i have a g12h100 which i like - its meant to be similar to their new g12k100
tried a classic lead 80 - very nice speaker, i think its the best of a lot of worlds
sidewinder - like this one too - transparent in a sort of way
G12B-150 - not keen, very scooped, a bit lifeless
i bet the g12-65 would be very nice too judging by internet rumours.
but if you want a 4x12, nothing will fix that - except trying to lift one :) i also wanted one, but i can barely lift even a 2x12... so ;)
i dont think you'll need to spend a couple of hundred quid. get a used speaker for 40 quid or something first. then wonder about the valves. mesa boogie valves aren't known to be bad - unless someone changed them for another make?