I am not familiar with what the various companies are flogging now.
As to full bore slugs, the Fosters are a washout for anything but little deer as far as I'm concerned. They expand to rapidly and lack weight. I'd much rather shoot balls.
The Lyman Sabots which are almost full bore & use field wads would be about the smallest sabot'd slug I'd use.

Round balls are too easy to not use them. Also, they can be of any alloy, and therefore penetrate as well or better than any soft slug.