I have inner tubes with the insas (235/85/16) on my CJ7, and run them down to 10psi, the only thing is you have got to watch they don't spin on the rim and break the valve. This tends to happen when you first fit them, but I have not had them come off the bead yet. On the CJ5 with the swampers (32/10.50/15) I don't have inner tubes, and I have run them down to 5psi off road without any trouble but then its much lighter than the 7. Most of the more modified vehicles that I see at trials run bead locks.
The inner tubes I have just came from a local tyre dealer, they were not any thing special.
I don't think wide rims and tyres need a inner tube