A slug gun is more than up to the task for hunting hogs. For those 100 yard and in shots, you will be fine.
I have a Browning BPS with a Hastings rifled slug barrel w/ cantilever scope mount. Out to about 100 yards, Mr. Piggie is in grave danger.

As far as the ammo goes, you will have to find what your particular gun likes. My gun has developed a taste for the "finer things" (aka 3" Federal Premium Hydrashock Sabots) ~$3.00/shell. With them I can get right around a 3" group at 100 yards if I am shooting off of a sled......in my hands.......not so much.....

The pump is nice for a quick follow up shot as well.