I'd second Rad. Although I'm brand new to the truck conversion group. Another idea is to look hard at all the rigs available out there to jump into and use. I know you want to save some money and build yourself. But, with the economy where it is there are lots or rigs available and dealing going on. I'm somewhat handy and had momentarily considered having a box built onto a used truck and finishing it myself. I fould what I think is the perfect rig for me sitting on a dealer's lot. I made them an offer that I thought was very fair to me and they sold it to me. It's hard to believe you could build it yourself for cheaper than you can find somebody that needs to sell one. I think maybe even the cheapest way to go would be a good used tractor hauling a trailer with living quarters up front and toys in back. That's if you don't need free flow between the cab and living quarters while driving down the road. You can pick up a great used trailer split up that way now pretty cheap. Good luck. I wish there were more people posting on here but the truck conversion segment is a very elite small group, hahahaha, not like a regular motorhome. Keep the thread alive too.
'03 Freightliner FL112, 295" wheel base, with '03 United Specialties 26' living quarters, single screw, Cat C12 430 h/p 1650 torque, Eaton 10speed , 3.42 rear axle ratio