I think a 10 inch barrel is a pretty handy length and I think it would be fine for the 218 Bee. You have to decide what you want to do with your barrel. If you want velocity, then you'll probably get about 25 to at the most 50 fps more per inch of barrel. If you want to carry it hunting, maybe a 10 inch barrel would be handier than a longer one. I like a 10 inch barrel Contender because then the whole gun will fit in a Camelback.
You are, of course, entitled to your own preferences but why the 218 Bee? If I were wanting a .224 caliber centerfire Contender, I would be going with some more modern and available cartridges like the 222 Remington, 223 AI, 22-250 Remington, etc.
As far as scopes are concerned, I also have opinions. I've sworn off Bushnell scopes since the Bushnell scope I had on a 500 S&W Magnum failed and they refused to honor their warranty saying it had been abused. I then had a Thompson/Center scope on the same gun that broke. Thompson/Center promptly and without hassle sent me a new scope. I have no experience with Weaver scopes so won't comment on them. The current handgun scope brands I consider are Thompson/Center and Leupold. I've heard Burris scopes are good but haven't tried any. I briefly had a 308 Winchester handgun barrel with a 4X Simmons scope on it that shot quite well. I've decided it's more economical to buy something good once than something bad several times. That said, a 218 Bee shouldn't be too demanding of a scope so an economy scope might just work fine for a long time. I doubt there is much difference in quality between Bushnell and Weaver.
