So the main reason I recommend against the hitch carrier is convenience. You lose access to the rear doors while it's on, it ruins your departure angle, and you feel the weight wagging back and forth.
If you do go with a hitch carrier, get a stabilizer. They're about $20 and make a huge difference. Also, either put lights on the hitch carrier or make absolutely sure the bike isn't obstructing your existing lights because that's a real easy excuse to get pulled over.
If you go with a Harbor Freight trailer, you won't feel the weight as much, it's easier to load, etc. The drawbacks are that it's harder to back up and you can't drive in the fast lane (in CA, limited to 55mph, not sure about other states.)
I'd recommend budgeting $80 or so for a back up camera. It's not necessary but it's nice to have. Mount it on the roof of the van, point it down, and you can back yourself up to within an inch of whatever you want. Makes hooking up a trailer simple.
Since it sounds like you're still in the bike market, I'll just throw out my recommendations for lightweight bikes in various price ranges:
Suzuki DR350 ($1,000-2,000)
KTM 450/525 ($4,000-6,000)
I hear good things about the KLX and XT and I think they fit in between those two in price but I don't have personal experience.