4x12 is probably what you want then! :D
Don't be surprised by it being more directional, though.
It really surprised me when I experienced it years ago. I'd wanted to get a 4x12 but couldn't afford it (or carry it!). Someone lent us one for a few gigs. It sounded fabulous on its own, but I hated it during the gigs. It was our sound-engineer (a physicist) who explained it to me when I told him what my problem was on stage - it's interference and diffraction when you use multiple wave sources.
If you google it, most of the examples will be about light as a waveform, but the same thing applies to sound-waves - multiple speakers in a cab set up diffraction patterns that result in "peaks" and "troughs" - louder and quieter places in the room - that we perceive as "the cab is a bit directional".
A 2x12's diffraction pattern is "spokes" (like a cartwheel) of loudness radiating out from the cab, stand in between these spokes and it's quieter. A 4x12 generates a diffraction pattern that ends up as cross-shaped beam coming out from the front of the cab.
It's more complicated than that, obviously, especially when you add in reflections off of walls, ceiling, etc. But the spokes and the cross thing are the effects caused by the speaker configuration.
A single speaker just radiates in all directions, no interractions with other primary sources of the same sound, so no peaks and troughs. So we don't perceive the cab as directional.
(Oh, and btw, the questions on speakers themselves, can't help you there, no experience on that side of things! :D)
