I think it's a mistake to judge truck/trailer capability based on weight alone. There are way too many other factors that come into play.
If you're going to be pulling a two horse, and making mostly local hauls, I think you'll be okay with a half ton. If you're going with the four horse, or doing longer hauls, or are in moutainous terrain, bump up to the 3/4 ton. Also make sure that the towing package is a real towing package, the dealers are sometimes misleading about what's in the towing package. A real towing package includes beefed up suspension, a transmission oil cooler and a beefed up engine cooling.
If you overweight/overwhelm a half ton, besides sucky gas mileage, you'll put enormous wear and tear on the transmission. Depending on how much hauling you do, you'll end up replacing the transmission in your half ton. Spend the money now on a 3/4 ton; or spend the money later on a new transmission.
Just my two cents.