Focus on doing a small line of cabs well and don't provide many, if any, options. This might be an unpopular opinion, but I find that companies who offer everything tend to not really nail it with any of their offerings. There are exceptions, but I think starting out you should offer a small and a larger that's effectively two of the smaller cabs in a single box. That could be a 112/212 or a 210/410. Make them ported and include some type of high frequency driver to appeal to the largest market share. If those do well you could expand to other more specialty cabs, but if you nail those you'll likely do better than if you have a super diverse array of cabinets.
Regarding ceramic/neo and Eminence/Celestion options: Don't leave it up to the consumers or even focus testing such as this. Find a driver that you, as the designer, like and design the cab around it. If the resultant cab is light enough to be competitive, loud enough to be competitive, and meets your tone goals when paired with your amp then that was the right decision. Everything else will be a compromise.
Quoted to double-down on the "like"
It's a crowded market; and it's also a market where you are competing against pre-owned units... dare I say you're entering a market where a slice of the pie you're competing against is 20, 30 + year old units by companies that don't even exist today!
I'd be more than happy to chat via PM if you'd like to hear how I think I did it wrong, maybe you can glean some intel that will help you avoid the failure I experienced trying to nudge my way to the big boy table.
Best of luck to you!
And to address the OP:
Neo only
One line of drivers that sound the same so mix n match works
impedance is a b!+(H..... we want 8 ohm 1x 10 cabs but we also want 8 ohm 2x10s. I have no advice what to do about that. .. maybe you can offer 8 and 4 ohm 4x10s so at least both 10" driver models have TWO cabs they can go in?
15s are very popular and always will be
Wrap your cabs in tough finish (it's pricey but holy crap Line-x is indestructible) and steel (grill, corner protection, maybe even connector plates)
Speakon. Combo even better. Neutrik NL4 capable though
Taller is better than wider, but you kinda shouldn't be concerned beyond all YOUR amps fit, width-wise.
Bug-eye grills are ugly (ok opinion not advice)
TILT BACK KICK-STANDS on smaller cabs are frikken the awesomest bestest thing, like, ever
Please please please join the (AFAIK) party of one (Mesa) and PUBLISH the excursion-limited power rating. This really should be standard. I know it's a depressing-looking number, but it really does provide useful info for people who need to carry the house.
Last thoughts:
Be honest. Please don't let marketing rear-end you down the line. You don't want to get nailed on warranty claims from folks that take "1000 watts" to mean they can dime all the knobs on their "700 watt" amp and be safe to dig in.....
This got damn long. I'm stopping.
Good on ya coming to TB for feedback; I hope you land on a "win" with this line.