Well, I NEEDED a sw 3500 with spouse 4 kids 2 150 lb Alaska malamutes, rack, canoe etc to tow a 6500-7000 lb loaded 24' trailer! Loaded 3000 lb onto empty truck weight! OP probably does not need a 35 series truck. BUT if he loads up a canopy, canoe, or other topper style boat, generator etc into bed, along with 700-800 potential lbs of hitch weight, he may very.well have 2000 lbs added to base weight of truck, as I would. A base gvwr 15 series will have pulling power, not so sure about payload capacity.....so a 25 be it an LD or typical HD 25 series might be better option. Also depends on cab style too.
So for most of us, we need to look at payload requirements, NOT series of truck. My regular cab 2500 has 300 lbs less payload per door sticker than my dually crew cab, along with 1200 MORE lbs of payload than the sw cc truck before that. There are some of the 7700 gvwr reg cab f150s with more payload than a diesel cc f250!
OP needs to think about payload needs along with HP gearing needs. Something many forget including myself once or twice.
Marty