Keep in mind that a well-sealed house will have minimal humidification requirements compared to a leaky one. There is no significant difference between the source of heat, forced air, radiant in floor, radiant baseboard ,etc in the humidity except that these might affect air leakage (forced air with ducts outside of the house envelope). I expect that you will find that in the same geographic area, compared to an old, leaky home, you will find that on those real cold days is the only time you will want the humidifier.

I don't think you can use the most common humidifiers in AC ducts when they are not used for heating. You are likely to get condensation running out of the ducts. I could be wrong, there might be a way to do it.

Are you going to install radiant heating throughout the house?

Thanks, that makes sense and i plan on the home being energy star and super insulated. I do plan on using radiant heat throughout the entire house.