O.P. here.
An update on my search for a single gigging cabinet solution.
I've located a 4 ohm Mesa Subway 212 cabinet at a brick & mortar store so as to give it a play through.
Problem is, it's located a good 2-1/2 to 3 hours drive (one way) from the house, and going on a week-end is out, (we're booked solid on the weekends through March of next year.)
I've also contacted a G.K. dealer a couple of hours North of me and was put on their "first to notify list" when they receive either the new 8 ohm, G.K. Neo IV 210 cabinet or a 4 ohm, Neo IV 212 cabinet.
Next up if these options don't pan out, I'll order a 4 ohm RevSound RS210 (which doesn't have a return policy), and hope I like it.
And, if all the above options don't pan out, I'll continue using the 8 ohm Avatar Neo 210 cabinet I gigged with for the private party gig and the two open to the public jobs we played last weekend.
(NOTE: I always have FOH support but, Sunday's job was an outside gig and I really wished I'd brought "both" of my Avatar 210 cabinets and stacked them as a vertical 410.)