Another motor to think about, altho maybe above budget, is the GM with the diesel. Mid 20's city, mid 30 hwy empty. Probably like all diesels, low to mid teens towing. It would/could be better at elevation if you go above 6000' frequently due to the turbo. Under 5-6000', not sure a turbo/super charged motor that is similarly power speced makes a really BIG difference in total towing fun per say. both do the job, but with different seat of the pants performance etc.
WHere you are in Wisconsin, A forced induction vs natural aspirated may not be that big of a deal. If you head to the rockies 3-5 months of the year.....yes a turbo makes a difference. One trip every 3-5 years, get the cheaper motor that does the job where you are, go a bit slower at elevation.
marty