All ABS shafts have the larger 297 U-joints. Older, non ABS D30 shafts can have 260 U-joints. If you're getting new U-joints, you'll want to get Spicer 760 (new version of the 297, fatter Xsection, stronger) that fits in your shafts.
The ABS tone ring is just pressed on and can be removed if you don't want it. Yes, it will fit in a non-ABS D30. Non-ABS shafts will also fit your ABS D30, you just have to press a tone ring on there or the ABS won't be so happy.
All stock XJ/TJ/YJ/ZJ Dana 30 shafts have 27 spline. You can upgrade to higher spline counts if you'd like, for $$. IMO, easier to just carry a bunch of spares!!