Not sure if you are familiar with Cargill or not but here in Iowa from what I've heard Cargill will actually put up the unit for you and you'll raise the hogs for them and be in a contract with them. Don't quote me on all that but I know a little about them but its definetly something to look into.
If you can get in contact with FarmerBoy or A1 (they are barn builders). They are the two best in Ohio that we have found. We are also trying to put up a barn. Perry Shoemaker is the Farmerboy contractor and he has been very helpful for us. I don't know his number off hand but you might be able to google it.
Hope this helps