For years I had no jockey wheel on my 6x4, then saw one on special for $29 - bought it and got a friend to weld the bracket on for free. I'd never go without one now! Remember to fit the jockey wheel on the left side (for safety - curb side, not road side!)
Yes, try to get high side. I have normal height and am really struggling to carry everything conveniently. Of course, I cannot get high enough side to carry the 12" dob base as well, but if the top was higher than the diameter of the 12" OTA, I'd be happier. I have plans for some form of canopy. I want waterproof and secure, handable by myself only, and cheap - all these are incompatible
but I'm working on ideas. Currently I throw stuff in and do my best to fit a tarp over - but it flaps and rain gets in! But given I'm packing stuff covered in dew when I finish observing, water isn't a problem. But anything of value (eyepieces etc.) are locked in the car.
A suggestion: see if you can fit a carpet in the bottom. I found I had an old carpet rug that is just the right size for my 6x4. Good for additional cushioning. But it gets a bit wet often so I just have to be sure to let it dry properly each time.
Can you get a trailer with Camry wheels so your spare Camry wheel is also a wheel for the trailer? I do have a spare wheel bolted on the draw bars of the trailer - but it sure adds some weight.