Another option is to select the equipment size based on the cooling load and add a dehumidifier to the duct system.
We used our heat pump with a Honeywell Prestige thermostat for dehumidifying beyond the cooling set-point and it worked well, but it would take the temperature below the setting. Last summer we installed a dedicated dehumidifier that also works with the thermostat dehumidification controls. That eliminated the temperature overruns and used a much smaller compressor than the one in the heat pump to perform the task.
Edapeman let me know how your system went because I have a company from Winnipeg most likely doing our 5 ton close to Birds hill park and its next energy.
I didn't dig up the old thread, but I read it. He mentioned coated air coils. Do it. I don't know about you, but regardless of manufacturer, I have been replacing a number of coils. Have read and understand formicary corrosion. I hope the coatings work. Anyone have any input?