I do not think you will really know until you actually start shooting. TC Omega/Encores can have really tight barrels. It would be my suggeestion that you start shooting projectiles distributed by TC, one of the reason that the bores might be a tad tight so that you will shoot their products.
Probably, but not positive, you will end up shooting an MMP HPH-24 or Harvester sabot. You may even need to shoot .451 projectiles instead of .430's. For now the the thinnest sabot you can purchase is the Harvester "crush rib" if you need to go that route.
If you are just starting to shoot ML's PowerBelts or Harvester SaberToooths may be the easiest option, the PowerBelts are expensive but are easy to load. A lot of people have a lot of success hunting with these bullets but I would not recommend themfor hunting.
Powder - might be the next advice, I shoot T7-ffg loose powder, but it is not the only option out there. Again starting out I might suggestTriple Seven pellets - easy to load hard tomake a mistake, but as soon as you are comfortable I would make the switch to loose powder - less expensive and allows you to develope a load for your rifle.
Your post does not identify you as someone that is just getting into the sport but if you are Cayugad has some really good write ups for this kind of request when he gets on line and sees this message I am sure he will respond with some great suggestions.