I recently bought some chains from them and they are the cheapest I have found. Select "Tractor Tire Chains" on the left side then scroll all the way down to the bottom to select your tire size.
The only other thing I will suggest is to get a Duo type chain which connects every two cross chains in the middleof the tire tread. The standard 4-link ladder chains can fall in the grooves between the cleats of standard Ag tires, rendering them mostly useless.
They should. I have never ran chains on a tractor, but have on several pickup trucks. As long as the set of chains is close to the right width, you can use wire to tie the ends up.
My Grandpa had a 1960 Ford, (that never left the farm), he had a set of chains from a semi on it year round. He also did not need a 4x4 to feed hay with.