Size tends to depend on taste and tow vehicle. I tow with a chev 1500 so that's not that critical. Second consideration is comfort. I'd go 5 x 10 personally. the 2 that I've built were 5 x 11, built on a 5x10 frame, and 6 x 12. both were a winter warrior type which has a back hatch that lifts up so you can stand in the back with a inside galley. We'd camped for 3 yrs in a 4x8 little guy which back than wasn't even 4x8 at the floor. You learn to really love you sleeping mate in one of those. Have to roll over as a group. any way we decided we were tired of trying to wiggle into our clothes on our backs and went with something different.
On tires the first had 13's the second had 14's and personally I couldn't tell the difference as far as towing went. again that's a preference unless you need the extra weight capacity than the 14's will carry more.
Both trailers had brakes but when I bought a new tow vehicle the brake controller I had didn't work and I towed the larger one without them in the ozark mountains no problem.
I've done 2 I sold the first after 7 yrs and the second developed terminal rot problem and the frame is in the back waiting to be the third. I'll build something alot like the second since it was about perfect for Trudy and me.


Here's pics of the 2 I did. We're currently camping in one that Mike built that's is alot like my first.
Anyway hope this helps.
Gary
Where ever we raise the hatch is home.
Darn blank states keep getting further away and we keep traveling slower ain't never gona get this map full.

