Help me to choose the right cam

As for cam I'd go with stock 440 375 hp cam or similar or like Comps 252H cam it's designed for all the things you want decent mileage, towing works with manifolds.
Also stick with the performer your not gonna see much over 5000 rpm anyways. As for CR 9.1 is a good number for a tame street engine but if you want to run the lowest grade you might not be able to when towing especially with a lazy gearing.