I know you can get a sampler pack of sabots, but not bullets that I know of.
I like the Barnes TMZ 290 gr. They are a little tight going into my Bighorn, so I buy the sabots from Knight that are for the BT bullets and loads easier.
The Nosler MZ are tight in my Bighorn, my buddy has to drive them into his Bighorn. They are a .458 dia, I don't know of a thinner sabot to use.
If you are ever near North Bend, I could give you some of each to try.
I use those SST for plinking. Cheap and accurate, but people have said performance on game was not great.