re: New Construction HVAC question

I am a building contractor. I had a home I built for myself that had a similar set up. I had 3200 sqft and foam insulation. It had the Lennox 5 ton 16 seer var speed unit with a 2 stage condenser. The 1st story was on one zone and the 2nd on the other. I was there 5 years and the house cooled great. I cant remember what series it was, but it was the high series, maybe signature series? It was compatible with their best thermostat. It never broke, needed service, etc. I paid about the same as 2 of the lower seer/non efficient models. It was more about trusting my HVAC guy and he recommended it for the spray foam house being multi stage and var speed. He ran a J Load and I would def have that done.
If it were me, I'd probably go with 2 units if you have regular insulation set up and 1 unit that has all the bells and whistles if you go spray foam.
Only one complaint on the Lennox, it had a loud clunk when the condenser shut off. They said it is a relief on the fan motor. It was pretty loud and sounded funny. I've worked with Carrier, American Standard, Goodman, and Traine. I would use Lennox again.