I would be inclined to look for a one ton with lower mileage, based on your weight and usage. You say you will be towing three times a week for work, might as well get something that is likely to be more reliable.
On towing capacity, after having had a wreck because I had too light a tow vehicle, I am convinced I want something that won't get tossed around by what I am towing when I have to hit the brakes in an emergency. My motorhome is 15,000 lbs, trailer is 9,000 loaded. Works great.