Well first off, where I come from this is a good way to start a fight (LOL) So what ever I say is just my opinion. I grow corn mainly for silage but if its been a good year I will shell some. I use what is called a dual purpose corn. Its what I would recommend for a food plot also. Depending on what area you are located will also determine what varieties grow best in your area. I prefer a full season corn 115-118 day, seems they can tolerate dry spells better. I also prefer one with a large stalk so it can stand late and dry down if necesary. I have planted many varietys and the brand that I'm usaully satisfied with the most is Hytest. One bag of seed corn plants 2.5-3 acres for my conditions. You might want to consider Pheasants Forever for your seed corn, I've never done it but I hear you can purchase RR varietys at a good price.

As for the Sandhill Cranes, there is a product that is enviro-friendly thats supposed to work and is called Avipel and/or Avitec...I have no experience with this, its just what info I have read. Not sure its approved in all states.
Crows sometimes give me trouble and I really haven't found anything that works all the time. I currently use a product called Kernal Guard it is not necesarily a bird repellent, but seems to make the corn a little less apealing. I have heard of old timers using Turpintine, but I have never tried it, was afraid it could affect germination/plant.

It could be a few members on this site with more info and ideas that might be more specific to your area.