For 300 yards absolute max I'd get the 223, nothing after it, just plain jane, 223. If you were going to have longer range shots out to 350+ yards I'd get a 22-250 or 243.
But for what you described the 223 will be perfect, accurate, flat to 300 yards (aim at the top of the fur for a 300 yard yote when zero'd at 200 yards). It's also cheap and plentiful with alot of selection available!
later,
scruffy