Personally I prefer 2x12's. Right now I've got a Vader 2x12, Avatar 2x12 and Avatar 4x12. All three of them have some form of an Eminence Legend V12 in them. The Vader has the stock speakers that were custom to Vader, but are basically tweaked V12's, and similarly, the Avatar's have stock speakers that are custom to Avatar but are basically tweaked V12's. All three cabs sound pretty fantastic. I've used the 4x12 at home but I very much prefer the 2x12 for that sort of volume level.
At reasonable volume levels, any of the 3 cabs can stand next to my buddy's MkIV through 1960a. The Avatar 2x12 would have the hardest time keeping up on its own, but we don't crank things too terribly loud so it would be fine--that said, I haven't tried it. The Vader 2x12 does great on its own but I do miss the extra thump when I'm only running through one 2x12...it just doesn't hit you in the chest quite the same way.
I'm not sure about the Quilter, I've never used it. I have a Magnum .44, Engl E840/50, and Matrix GT1000FX. The little Magnum poweramp is surprisingly loud and sounds surprisingly good. My biggest gripe with it is the power supply and the lack of on/off switch, but those are relatively minor gripes. If you want cheap and portable, its a good way to go, but it will definitely be under powered compared to other options out there. The Engl sounds incredible, but it is a tube amp so you lose out on power amp modeling and accuracy & such. As far as tube amps go, it does seem relatively clean though. I actually preferred the tone with PA modeling on, but I could also tell it was over-hyped and didn't sound "right" just sounded a bit better to me. Now I'm running the Matrix and its pretty awesome. Tonight will be the first time I get to use it next to the MkIV rig and see how it stacks up power wise, so I can update this and let you know.
So, all that aside, some basic info you should share:
1. Whats your budget?
2. Whats your musical style?
3. What kind of friends are you gonna play with? I.E. other guitarist, bass player, drums, tuba, keys, etc?
4. Whats your location? Some cab choices definitely change based on region & availability.
Off the top, I would recommend a mesa/orange/engl/avatar/peavey/H&K/etc 2x12 with a Matrix GT1000FX poweramp. Buying used, you could put this together for around 800-1200$. 650 for the PA and 200-500 for the cab.
https://avatarspeakers.com/shop/guitar-cabinets/contemporary/g212-budget-contemporary/ This is a great deal on a brand new Avatar 2x12 with v30's which a lot of people love.