Buy what you like,,,
You can go crazy debating what to get for towing. Get something you like for interior space as well. We went with the Toyota Tundra Crew Max. For the towing capabilities and the massive space inside for our family.
Diesel trucks are cool too, but prices of diesel off set the MPG you save vs gas.
A simple K&N air filter will help a little as well. I use them in all vehicles even the wifes...
2011 JAYCO JAYFLIGHT G2 Rl