I have one of those HF trailers in the 4x8 deck size, got probably 5,000 miles on it, few years back I drove it all the way to Tennessee and back fully loaded from Maine. Usefull tools. I made sides and stuff that bolt down to it and come off quick by using eye bolts like you have on the deck I assume for bike tie downs and a wingnut with a washer for the bottom, Gives you and easy way to have a hand removable thing you can quickly bolt on and off when you need it. Might make building the front wall simpler.
One tip on the wheels, the bearings on those hubs are metric and can be hard to find locally if one goes bad (HF doesn't seem to stock them either). I had a hub casting crack on mine and I was stuck a couple weeks waiting for parts to arrive before I could fix it because of the bearings. I've made a point of keeping a spare bearing on hand just in case since then. (they are an oddball 25mm size, I get mine from redtrailers.com) You might also want to check the bearing grease, mine needed to be repacked right off the shelf. Look after it and these things work hard for the money, my trailer doesn't owe me a cent.