I think the jeeps are narrower than a 40. They may also be made for a lighter vehicle, with no good anchor points for your 40 body/frame. There may be somone in your area with a tube bender that can help make a basic bar/cage for materials and beer money.
It looks like absolute ccraappola! Trust me. Jeeps and cruisers don't mix. I sold quite a few parts that came in mine when I bought it that were jeeps stuff for cruiser made and the prices are not that bad. You will sleep better in the end.
artie, a friend of mine has his two aftermarket roll bars for sale in long island, one is custom full cage that he took out of his truck the other is an old con-ferr roll bar that is similar to stock, but pretty cool looking. I don't think he's going to want much money for either one because he's building a new cage and I could bring it down to jersey with me next time I come...PM me if you want pics.