Playing it straight, I'd recommend a bolt-action rifle. Almost any of the "basic" US factory rifles will shoot quite tight groups, or can easily be made to do so. The Remington 700 is said to have, basically, the best "out of the box" trigger. I know from experience that the Ruger Mk II needs to have its tort-liability trigger replaced with a Timney or equal.
For open-country hunting, some equivalent of the Leupold Vari-X II in 2X7 or 3X9 will serve. Giant lenses don't add enough extra light, generally, to be worth the extra cost. Unless you're primarily shooting prairie dogs at 350 or 300 yards, the higher magnification is not really necessary.
To me, the .223 is a varmint cartridge, not a deer cartridge. A close-range neck- or heart-shot will indeed kill a deer. However, a less than near-perfect hit can mean a lost deer, where a "real" cartridge like the .243 or larger will make a more serious wound--more blood trail, or a better chance for a coup de grace.
Is this a start?
, Art