Like others have said 1/2 ton will do it OK, three things are important when towing and it varies depending on whether you will tow a lot or for longer distances etc. For short hops basically anything will work within reason.
first issue is wheel base, shorter vehicles may have the power to tow but their handling towing is shaky, so is there stopping power especially when you have to do it quick. Longer wheel base vehicles will track better down the road and handle the torsional loads of road variances up down and side to side and the wind etc. they are also a lot more stable under manuevering and braking conditions.
second is not power! second is braking, smaller vehicles generally have smaller brakes, calipers drums and swept area on them to dissapate heat and apply pressure. Ask anyone who tows a lot, in varied hill and highway condition who has had to stop a vehicle with 5-7 thousand pounds behind it hard because granny pulled out in front of you, it is definetly the second most important thing if not the first. That depends on what sh!t has happened to you, because as you know some people live charmed lives inspite of their IQ.
Third is power, basically bigger engines, V8's especially actually are more effiecent because they make there power (torque) in lower RPM ranges. I have owned some very tough V6's that towed with but they had to work much harder and the fuel economy went way down where as the V8's went down only marginally.
Also a vehicle that you should consider if you can find one in good shape is the older F150's if you want a half ton(various cab seating available) with the older fuel injected straight 6 (300 cubes) it towed well got great gas mileage and had more torque than a lot of V8's. I worked for thirty years with a cop who towed his 30' camper to British Columbia from NJ every summer with his family in a F150 with the afformentioned straight six and never broke down once, had over 300G's on the first one when he finally broke down and bought his second.
Me persoanlly I went with the Super Duty F250 with the 5.4 V8. Because I tow a lot and also go hunting all over the place and needed large carrying capacity and good off road capability where I go. Plus I unlike some Windy fellows around here My balls are huge but they are attached and in my pants where they actually perform their function
