That's a sweet looking rig. Personally, if you have no intentions of competing, or vending, then I wouldn't get something that big. If you've got your heart set on a horizontal off-set, see if he can make one half the size. You'll have plenty of room for a big party, and could compete with it if you change your mind.
Just my two cents. I would love to have a trailerd unit like that, but I have no use for one, my WEBER, NBBD, and UDS have all the room I need.