A truck with a canopy, or a truck-based SUV are the two real choices. Any 1/2 ton-rated rig will manage. How much 'power' is enough really depends on your driving style. Today's truck motors are probably double in power of a truck of 20 years ago... and people seemed to manage big trailers back then.
Get something with a 'towing package' which will usually entail a transmission cooler, lower gearing, and a 7 pin harness to plug in. Heat kills, so if you are going to be towing it hot climates with long grades, an engine oil cooler is good to have as well.
Any dually is going to be a 1 ton, so you are getting a lot of 'advantages'... huge payload, huge towing... extra safety of 4 tires in the back... but with the big trucks comes big repair bills when all that heavy-duty stuff wears out. Although pulling a 5000lb trailer you might never really give a diesel dually a workout.
I went with a used Sequoia 5.7l, 4x4. It's our only vehicle so it needs to do a lot of other things that tow. One kid, one dog... and sometimes the need to stuff 7 people inside. A Suburban, Armada... same idea.
We looked at Ford, but the dealer here is a bit of a turd, and we've had good experiences with used Toyota's. Their own extended warranty is quite reasonable, and they manage it through Toyota. Dodge has some great incentives frequently, and recently they were giving away the diesel for 'free' (compared to the gas model). All the manufacturers have good financing on trucks right now it seems...
Buy what you like... there really isn't anything that won't work.