RE: .223 or .22-250
Unless you handload, there really aren't a lot of options for factory loaded cartridges that are suitable for deer. You'd be better off with a .243, or even better, a .25-06.
My .223 handloads shoot 55 gr. Sierra Gamekings. I have been really impressed with their performance on hogs. Haven't shot any deer with it, but if they kill hogs, I can't imagine them not killing deer.
Also, not all states allow .22 centerfires for deer. Check your local laws to make sure this is even an option.