I'm not claiming this is the best setup, but it's what worked for me in my Omega.
1) I am using the 209 primer system that came on the gun. No problems. I would try it first, there may be no reason for you to change (don't fix what ain't broke!).
2) I use a .44 caliber Hornady XTP in a Hornady sabot (green sabot). These are fairly easy to get down the bore, unlike the .45 XTP and black sabot (took both hands pulling HARD on the ramrod). The .44 XTP/green sabot will shoot 1-1 1/2" groups at 100 yards out of my Omega, but is not what I would consider to be a long range bullet (say past 200-250 yards).
However, where I hunt those shots are not common.
3) I have only used loose Pyrodex Select so far, and am completely satisfied with it's performance. I can load several shots without cleaning. I may try standard grade Pyrodex this year just because it is more available around here.
4)My gun came with a 3x9 Nikon mounted, a package deal from the gun shop. I really like this scope, although it is probably more than what I need for where I hunt. I would most likely choose a 2x7 or smaller, but I am impressed with the Nikon scope, it compares well against my Leupolds.
My opinions, FWIW