I would just go with a +'92 cage. Although even those will require some work to use. I think the problem you will run into using a TJ cage is that the front arms aren't going to work without some fabrication. The pitch of the TJ windshield is sharper then the YJ's. I would think there might be some differences in the floor mount but thats pretty minor. For the rear you'd need to reinforce the wheel well with some steel to make sure it doesn't punch through. I would highly recommend welding the TJ cage together the main hoop is 3 different parts that are bolted together.
Since you have a -'91 cage, why not have someone with a welder and tube bender make the rear support?
I could ask Pete about that article, he's on another forum that I used to hang out on, if you want more info.