Optima Elites are good rifles from all I have read. I am sure they will serve you well. Since it is a .50 caliber, first thing you need to consider is what legal projectiles are in your State, and what kind of ranges are you expecting to encounter. Also if scopes are legal or not. From there choose a projectile that will get the job done as efficient as possible. Also check into whether Black Horn 209 powder is legal and if you can get your hands on any. That is a great powder and with a good hot primer should shoot real well in your rifles.

There are lots of other things you will need. Cappers and de-cappers. Primers, loading jags, short starters, brushes, solvent, oil, breech plug grease, just to name a few. Get a good powder measure with a see through design with a cut off funnel. And if you can not get Black Horn, try some Pyrodex RS or Triple Se7en 2f. You might want to pick up some 250 grain Shockwaves, 300 grain XTPs and some different sabots...

But the first thing you need to do is clean your rifle. Learn all the parts of the rifle. And read your manual and know it inside and out.. good luck with your rifles.