JSK,

Curious,how does the savage compare to the H&R for groups? I know the H&R's have been known to be very good for slugs, is the savage touching it?

Silver,

You have a lot of options here. If you want a pump a remington 870 or a mossberg 500 is good. You can buy barrels for them with cantilever scope mounts. This way you can swap your slug and field barrels whenever. These are decently accurate.
If you want a dedicated slug gun an H&R Ultra Slug hunter is a great choice, although just single shot. The savage 212 and 220 are becoming very popular. And I've heard all good things. This is a bolt action, once again this would be a slug gun only.
I have a Mossberg 695. Its a bolt action 12 gauge slug gun. I haven't gotten a chance to work with it much though. But I'm sure it'll shoot well once I find a load it likes and get a decent glass on it.
Your range will be in the 100-150 yard range, with a few exceptions. There used to be a guy around this forum that was shooting out to 200, but I don't know if he is still posting. SHooting farther can be done, but that'll be up to you.
As for glass, get the best you can afford, you won't regret it.
Hope that helped
-Jake