Although I don't have a lot of time with TTs, my wife and I looked for about the same thing as you.
As you are 6'2", I would caution you that the length of the bed isn't the only thing you need to worry about. Some of these small trailers don't have much headroom. Be careful to check, especially with trailer like the R-Pod, that slope down on the ends. The 180 that you mentioned has the bathroom at the rear, which means you'll most likely be ducking your head as you use the sink or toilet.
Also, as to the fridge size, think about what type of camping you will be doing. My wife and I decided that the 3.2 c.i. fridge that our camper came with won't be a hinderance to us because most of our camping for the next few years will be mostly 3-day weekends. If you are planning to spend a lot of time in your camper, say anything over a week or two, you'll definitely want the 6 c.i. fridge. Otherwise, you'll be hitting the grocery store every 3-4 days.
The advantage of a double axel rig is that it tows more steady and if you have a flat, much more controllable than a single axle rig. The problem for you is that a double-axle trailer will add around 800 lbs to the trailer weight and you have a pretty low tow rating on your tow vehicle.
