Anyway, welcome to my teardrop build thread. In actuality, I started planning this a few months before joining this site back in September. I'm a big reader and planner so I appreciate everyone's input on this site. Based on the consideration of many factors this I roughly what I have planned:
4.5' x 9' teardrop (actually a few inches larger than that each way - 55"x111").
79" outside wheel to outside wheel
31x10.5x15 BFG
ASR2KHDS01 Timbren axle-less suspension w/e-brakes
And that right there is where everyone should really start - with the base dimensions and the suspension. Why? Because everything else is built off that. Want a comfortable door height? How do you know if it will be the right height or not if you haven't yet built the suspension? Want to fit an X width bed? Well, that drives your width. Driving offroad and want the track width to match your vehicle? Better start measuring. In short, there are many reasons to look at the suspension and base dimensions as very crucial design decisions in your build. It probably took me longer to come up with these few decisions than anything else. And I had it easy because I went with an axle-less suspension.
So here is what I came up with for a frame:

I'm building the main frame itself out of 2x3x.120 wall tubing. The tongue and bracing is 2x2x3/16. The additional cross members are either 2x3x.120 or 2x2x1/8 angle.
The fenders are braced with 1x1x1/8 angle and are built to be bolted on to the fender supports that are attached to the main frame. This will make building the cabin in place on the frame a much easier prospect since they can be removed during the upper build process.

The rear supports I am building out of 2" & 1 3/4" Telespar. They will be held in place by a couple spring loaded pull pins.
Lighting is courtesy of LED lighting by Optronics. The side marker lights are recess mounted in rubber mounts while the rear lights are protected on the bottom with some metal guards.

Ground clearance from bottom of frame is about 18". Given my mild off-road aspirations (base camp style), this should be plenty.
The white box is a 10 gallon water tank mounted on a bolt on support tray that can be unbolted for maintenance/replacement.

Well, that's it for now. I'll post some more pics soon of current frame progress and then eventually some mockups of the cabin itself after I get them cleaned up a bit in sketchup.
P.S. - If you couldn't guess what BeST in "BeSt One" stands for...blood, sweat, and tears.