Geo,
not to be the upsell, bigger better type response......
Consider the 23"
I came from an 13", 18", and 24" ceramic set and found the 24" to be my best option for most things. I called the 18" my working grill because I was steadily moving things around to make it all work out.
If you are considering having one charcoal a 19" alone may not be the best option. As Dennis said to me when I was looking and trying to decide, if you think of the size of a gas grill then go bigger. A gasser is usually a 24" to 30" size. The key here is the word grill.
If you break down your cooking habits then you will better be able to assess what works best. For me, I am a griller 90% of the time. I like the grillestate (see what I did there???) for grilling different cuts.
May I also suggest because you mentioned rotisserie to go with the bigger belly. I like the larger foot print for spinning meats
One of my complaints about a 24" ceramic grill was that they took longer to heat up and stabilize and it had terrible charcoal consumption.
When I switched to the 23" kk, I learned quickly that it heated up quicker than my 18" ceramic for one and two the charcoal consumption was incredible. So much so that I really have no need for my 13" ceramic anymore.
If you think about it, 19" grilling space for even just 2 people will fill up in a hurry. Throw on a few items, or vegetable and you are jammed for space quickly. Also that extra space helps with long cuts of meat like ribs, brisket etc. without having to manipulate the meat.
But.... with all of that said any size KK is a great machine. You will be happy with whatever you decide. Since you are thinking about the tall and not the table top I think the 23" will be a perfect size for you.
here are a few cooks to help show grill size for you
23"
Cant wait to see what you go with
Last thing.... a good friend on another forum just spun a 14 LB. turkey on an 18" ceramic without issue....