Your most likely in an area much like south central alaska.. 35F water right out of the ground.
That can be a good thing.. as I get away with some things that others can not, softeners on water with iron up in 20ppm.
If you are looking for a unit that is going to last YEARS.. stay away from the GE type units as I see them and others with the same valve last only a few years around here and the iron is hard on them, iron will work on any unit that you get..
Stay away from the air suckers.. as the iron will build up in side the pipes from where it is pulled in to where the filter is at, 1" going down to 1/2"...
Water has a salt taste? only RO or Distiller is going to change that.
If one can try to keep things simple. big blue 20" with say 58 micron filter... might be changed every 4-6 months for some of the iron, then a 1.5 cubic foot unit and if possible have a turbolator in it so that the resin bed is changed over every cleaning.
In my spreed sheet the 1.5 cubic with a full capacity of 48000 but run at a capacity of 40k would run you about 1.5 bags of salt per month.