Doegirl75
I am biased, I know that, but I think you are really going to like the 50 vs. the 45. One of the loads I am using in all of my inlines is a 10mm 200 grain XTP in a MMP 50/40 sabot - talk about a sweet shooting setup...
Some states do not allow .40 for ML hunting some do, Idaho doesn't during ML but it is OK during regular rifle season so since I hunt all year round now with aML it could work for me.
I think your Banner will work just fine, especially if you like the scope. If you do decide to make a change and want to stay in the inexpensive or less expensive area take a look at the Swift Premier line of scopes. I got a 2x7x40 the other day and itreally shows promise, can not fiure out what I am going to put it right yet, but it will end up on something.
Good luck and Good shooting