Donnie,unfortunately the days of haveing a flock of free ranging pigeons living in a barn is almost over. With all the protectection of hawks they are so abundant that you just can't hardly do that anymore. If you wanted to try I sure wouldn't invest in anything but common barn pigeons,that way your losses won't hurt so bad money wise. On the other hand if you have a nice extra room in the barn or loft they are a fascinating hobby. And you can go as expensive as you you can afford. There are as many breeds as chickens almost. I have raised them for over forty years and am still fascinated by them.
Rabbits are also fun and there are lots of breeds to choose from.Have to decide if you want meat rabbits or show or both!Its hard to make a lot on them unless you are breeding and selling stock of popular breeds or if you have a for sure meat market or pet supply source.All that said they are fun to mess with and not too difficult to raise. Give them a try.