I prefer 2 speakers on stage per amp, but there is nothing wrong with the 1x12 ac15 format, its hella loud, especially with an actual celestion blue or H30 at 100dB sensitivity (maybe too loud for most people).... weber's blue dog is slightly less efficient but is a little less bright, personal I prefer all the treble from the current RI celestion blue, its never harsh and sounds closer to an old blue in very good condition than the weber.... the weber sounds like an old blue that was stored in a humid basement, not bad, just different.... but I digress
I am not impressed by the build quality of the current Chinese vox ac15 and 30, the older ones are a little better and have better cabinet wood to boot... all of the current voxes other than the handwired stuff is a little too bright and stiff sounding compared with a vintage JMI, but not in a bad-assed way like a matchless DC30, ore of a shrill and sterile way, but its still a solid little cathode biased rock machine.... maybe a weber blue dog would help to tame the hyped treble (vox went crazy with the treble and power filtering to make the custom classics sound like middle period Beatles recordings that actually were done with ac50s, ac100s and UL series hybrid amps all of which are completely different circuits with a different feel and sound)
frankly if I needed an affordable 15 watt cathode biased el84 amp I would go a different route than the current ac15... but if they started offering it as a 2x12 now? might be worth it if you are into the 2x12 sound like I am.... otherwise I recommend getting another brand of 18 watt cathode biased amp as a head and cab setup
what's your budget?
also, there are a vox-a-likes that outchime even vintage voxes... the legit vox sound is VERY balanced with a healthy dose of upper midrange and surprisingly strong bass, the normal channel takes pedals wonderfully, the top boost channel takes pedals well as long as you avoid extreme tone control settings, but that's part of the fun of the top boost channel.... also, your first ac style amp will make you wonder why you bother with effects because it sounds so good on its own
also, I love blackface fender deluxes/deluxe reverbs and princetons/Princeton reverbs, but they are a different animal entirely than a vox.... a tweed deluxe has more in common with the vox design though the voicing is very different... blackface fenders really take pedals well, better than any other vintage amp design
so anyway, what's your total budget?
also, my son is 2 (and he won't go to sleep tonight so hes sitting on my lap while I am typing, so sorry if this was a rambling response with lots of typos), maybe we should arrange a marriage and pool our gear?