From what I've read over the years, 50/50 is pretty standard among survivalists, but YMMV. I have an article called "A New Staple Food" by Kurt Saxon that recommends 25% each of pinto beans, corn, wheat, and rye. Unfortunately I can't find that article online any longer; it had some good recipes and ideas in it. (I like Kurt's survival stuff but not the racist position he espouses; eat the hay and spit out the sticks, so to speak!) When I get some time--perhaps next weekend, when I'm temporarily "kidless" and have an extra day off--I'll type that article up into a post for those who are interested.
Protein combining isn't necessary for healthy adults, as the body does that naturally over a period of a day (it takes foods apart and recombines their chemical constituents to get the needed mix of amino acids). Your activity level and a variety of other factors will cause all your nutrient needs to vary from day to day, so perhaps planning for a set combination might not take care of everyone's needs. A combination of whole grains, beans, and veggies will provide all your macronutrients, if you're consuming enough calories. Some survivalists focus almost exclusively on calorie counts; some worry about protein levels; I personally prefer a balanced nutritional approach featuring high-nutrient-dense foods. (Except for the occasional Twinkie!) I try to eat a nutrient-dense diet now, for the most part; not waiting for the feces to impact the rotating airfoil.