Help with plans for a weekender/squared 4x8 camper?

Hi all, I am new to the site and love all of it. I am recently introduced to mini trailers, and have been a tent camper forever, but want to try my hand at building a camper to tote behind my jeep. I have searched and searched for some plans to make a squared off camper for my 4x8 harbor freight trailer. I am wondering if anyone has or knows where I can get ahold of some simple plans with a simple galley and empty interior. I have found some nice drawings on this site but no plans other than the rounded ones, which I have no faith in my skills to create round things out of flat wood.
I would even like designs for a camper that extends over the wheels for extra interior space, if there's any chance for that...So, here I am, thanks for any help.
Dana

Dana