SXS
I, also, am not sure about what you are looking for.
If you want either a SXS or an O/U for Upland hunting, the choice is very personal. I use both. My favorite, personal choice, is a SXS. I very much enjoy the way SXSs point....find that they are more "natural" (but that is me, someone else might feel the same about an O/U or a pump).
The business about slugs and buckshot and bears was unclear. As noted by another poster, you should be able to load a rifled slug into one of the two barrels, at least, and fire it safely unless the gun is choked Full and Full. If it is choked that tightly, it is really not a good choice for Upland hunting. In fact, IMHO, if either barrel is choked Full, you'd be better off looking at another gun. Typical Upland choking is IC/M and a rifled slug will work out of either choke.
The Savage O/U combo has a long history but the rifle barrel is not known for accuracy.
Pete