Lens 1. has image stabilisation and was released in 2010. Lens 2 has no IS and is considerably older, dating from 1995.

The one with image stabilisation is better as it will enable you to shoot longer shutter speeds when necessary in dim lighting conditions. It is also a more modern design with sharper optics.

If you can't afford the IS version you could get by with the non IS by attaching a monopod to the tripod collar, but you'll lose mobility with this approach.

In wedding ceremonies, people often move quite slowly, so you may get away with 1/60 or even 1/30 for some shots. The IS will let you do this hand-held; without IS its unlikely you'll be able to hold a 200mm still enough to avoid blurring much less than about 1/150 (faster on APS-C cameras). So that would let you put the ISO/aperture down two extra stops for the slow/stationary moments. At the 70mm end there's not much difference.

When people are dancing, talking, etc you'll be above 1/100 anyway, so not a huge difference.

For a handful of shots (flowers/rings — still life) IS will maybe even get you down to 1/15, so 3-stops of extra range on ISO/aperture if you want it. But the tripod/monopod would probably not be a big hassle in those shots anyway.