The Tikka T3 in a factory rifle is likely the best offering today at a very reasonable price. However if you must go custom, 260 or 7mm-08 would be my choice in the short action or the 25-06 or 280 in a long action. All of these cartridges will handle any deer and also take game animals like elk and moose, has factory ammo available for it, and are easy to reload for once you get set up.
Good luck!
Good luck!