That Featherlite is a nice looking trailer. Look for removeable or low-clearance fenders or be prepared to possibly have to climb in and out the car window when it's on the trailer (Dukes of Hazzard style LOL). Low-sitting car doors and trailer fenders don't like each other. Get the biggest wheels you can on the trailer (usually 15" or 16") and keep the bearings greased.
As far as 1/2 ton vs. HD P/U's, if there's a possibility that you'll be towing more down the road, then yeah HD may be the way to go. Otherwise the 1/2 ton is adequate for a light car and light trailer. Where you were originally considering a mid-size V6 the jump to a HD is a big one. With a HD you'll have a stiffer ride and yes depending on the truck a MPG penalty. Typically a higher buy-in cost as well for the HDs unless you find the right deal of course. I'm not knocking HDs, just a right tool for the job kind of guy I guess.
One more thing to keep in mind if you get a used truck that's lifted with bigger/heavier tires is that the lift and tires will impact your comfortable towing weight limit and mileage (I had 35" 80 lb. mud tires on my Titan and they looked fanstastic and took me anywhere I wanted to go off road but mileage was around 12 on the highway without a load and significantly less when towing). Stock height and tire sizes are the better bet for towing. That Stillen Tundra does look good though
Man this discussion has me missing my truck and wanting one again! Before the part out:
