I think you'll like the difference. I run a 50 tooth on my mountain bike.... never tested it on any big hills, but I pull a trailer for groceries/laundry etc. real good take off.
will your bike pull you up your hills, even slowly or do you have to pedal too?
I lived north of springfield when I was a kid....so I know about them Missouri hills.....and curves. here in kansas, everything is square & flat.
You should be able to get a 50t sprocket from Mike at http://www.simpsonmotorbikes.com/ . I looked on his site but didn't see them, if you e-mail him or give him a call (# on his home page) I'm sure he can hook you up...Kelly