Springfield armory used to make one, called the M-1A. Semi auto version, had the magazine etc. Was esentially for targets but looked almost like the real deal and was very expensive. Don't know if they still make it or not. Probably good google and find out fast enough.:)
[Stoopid gun n00b question: if I wanted to purchase a M-14, what is the closest I can get legally? Make, models, and availability please.]
Check out Springfield Armory's selection, if that's the rifle you want. SA has a new M14 called the SOCOM II that has a bunch of rails for hanging SureFires, vertical grips, and sights. Yes, these are VERY important and, at the very minimum, a light is mandatory on any rifle you'd grab for protection. Price should be $1,500-1,800 for the rifle. Accessories are extra.
Check Springfield Armory or Fulton for the M1A. Multiple configurations and prices are available. The principle difference is the M1A is semi-auto only. M14 was select fire. Pricing varies based on barrel quality, stock quality, embedding or not of the action in the stock.