First the background (skip right down to the question, if you'd like):
I'm in the NYC area, where humidity isn't a huge problem, (but it's an annoyance), and electricity prices are a problem.
I'm quite interested in a two stage system with humidity control for this reason.
I've had a couple of contractors come around and, they haven't done manual J yet, but they both estimate I need about 3.5 tons. One gave me quotes for a 4T single-state 15 SEER unit, and a 4T 21SEER unit (carriers), and another was pushing the "comfortmaker" at 3.5T 15SEER.
It seems comfortmaker is carrier's unbranded line, and they do offer 2 stage units, and I've looked things up, and you can get a c4a648gka with either FVM4x48 (16 SEER total) or fvm4x60 (16.5 SEER total), and these both can take humidity controls to run with slightly lower fan speeds for humidity control, etc.
The problem is, it seems that the two-stage units don't actually come in 3.5T..
My logic is, that with a two stage unit, a little oversizing isn't as bad for either humidity, or energy usage: It just means you'll be running on the low stage a bit more than the high stage.
Is that logic right?