Texas Rob, looks like you're post suffered from premature ennounciation.
Just about everyone who has a WSM has the same discussion. Folks with the 18.5" love them. Folks with the 22.5" love them. You won't go wrong with either.
It is just my wife and me too. The 22.5" may use more fuel than the 18.5" but I'm not concerned about that. I stock up on KBB when it goes on sale for half price during the April to Labor Day holiday period.
I only use the top rack the majority of the time. I can throw two full, untrimmed racks of spares on it or a full packer, one of which will probably go in the smoker next weekend when company arrives. What I like best though is all my oven pans fit in the 22.5", including the large turkey roaster that I fill with veggies and put on the lower rack as a drip pan while the 20 lb turkey is roasting on the top rack on a turkey canon. I also use 15" paella pans (about a 20" total diameter) almost every time I smoke. I get very creative using them from drip pans to making pizzas in the smoker.
Like I said, you'll be happy with either. If budget is a big concern, get the 18.5.