YJ and CJ7 tubs are very close in geometry. People are upgrading CJ's and early YJ's to the "family style" roll bar. Around here they bring $100 to $150. I had considered one for my cj7 but decided to keep what I got since I don't have the back seat in very much.
They are a good investment if you have rear passengers or children, gives them much more protection than a stock cj or early yj roll bar.
I've seen them for sale on craigslist and ebay but usually don't last long. Keep your eyes open and might prepare yourself for a drive. The closest one I ever found to me was 3 hours away.