I like the M1A (M-14) but if cost is the issue I would go with the Mini-14. I also pack the M1911 45 for close in. Reality is if you are not intimately familiar with your weapon then a Remington 870 12 ga is the best (How many 600 yd shots are you going to get with the big guns?) My wife has the 870 to back me up and pickup any 'leakers'.
and with a rifled barrel and the excellent sabot rounds available, your wife, with the 870, can assist you with some of the long range shooting.