I think the "perfect deer cartridge" is a subjective thing. It really depends on a lot of things, and that is why there is no "perfect" one. Where Im from the .30-30 has been king for decades. But out west on the plains a .30-30 wont get you much when your shooting at 150+ yards. Some say its the 30-06. Some the .300 Win Mag. Ive heard good things about the 7mm-08. What you really need to do is determine a few things. First is distance: Will that round kill effectively in your set Max range? Are you looking to drop an animal, or can you afford to trck (here in the North a straight drop kill is best because of the odd chance the deer might run into another hunter, since pressure is high here.) Is ammo readily available (in your case there should be no problem.) And finaly, can you live with any shortcomings the round you choose might have. A good addage that seems to always be true is this "shoot the biggest you can handle." If you can shoot a .300 Win Mag and smile, then go for it. If you can only take a .243 fine. Just know what each cartridge is capable of. Im sure this probably doesnt help you much, but its good food for thought.
Brian M.