RE: debate
First, welcome to the board!
Second, with good 100 gr. hunting bullets, the .243/6MM will take down ANY Whitetail, and is a very good minimum deer caliber/varmint caliber.
Third, not knowing your experience with centerfire rifles, or your tolerance for strong recoil, I would NOT recomend a 7MM RM, or .300 Magnum! While I use a 7MM RM on deer, I would be the first to tell you big calibers are NOT needed for deer sized game! The middle calibers such as the 25-06,.260, or the 7MM-08 are very good choices. Good luck!