MakeShift has a 6x12 single-axle with electric brakes and a ramp door that weighs about 1500 lbs empty. I often pull it with my 2014 Ford Escape, which is a small SUV with a 3500 lbs tow rating. I'm only really comfortable towing it when it is lightly loaded, however; as was already mentioned, 3500 lbs is on the low side for towing capacity and I don't like pushing it to the limit (you definitely feel the car straining when you do). This means that when we go on road trips to regionals with all our stuff packed in there, we like to find someone with a beefier vehicle to tow it, which hasn't always been easy.
If your trailer has electric brakes, then it will have a 7-pin (round) electrical connector. This isn't as common on smaller vehicles even with towing packages, which more often have a 4-pin (straight) connector. I had to have both a 7-pin connector and an electric brake controller installed in my Escape to make use of it.
I second the utility of E-track for tiedowns - it's super useful. What we did was install one strip on each side wall right down at floor level, and then another strip above them about 2' up. Since you can move the tiedown rings around on the track you can pretty much fasten whatever you want with that high/low combo. Another thing you can buy for E-track is
hanger brackets for 2x4 wood. This allows you to make some cheap load bars to keep your cargo from rolling around without necessarily strapping it down.