Source for thornless honey locust?

I am in Muscle Shoals, AL (zone 7a) and we are starting our first two trios for the fruit orchard, but we are unable to find a source for thorn less honey locust.  I've found a few on Etsy but there isn't a nursery within 150 miles that carries them.  

Our reasons for picking this nitrogen fixer are multipurpose, we will run sheep and chickens under the trees once they are established so we want the pods and not the thorns.  I don't want to have to mess with flat tires, and due to the animals I don't want to use black locust and deal with potential poisoning.  

If anyone knows of some, or has other suggestions we are open to them.  

We got thornless honey locusts from Cold Stream Nursery last year, and they were very nice seedlings, with no thorns.  The plan is to graft large-podded cultivars on them in a year or so.  We've also found a number of thornless trees in neighbor's pastures, and have dug up suckers from them.

Honey locust grows easily from seed. Seeds for the thornless variety are available from Sheffield’s Seed Company. Sheffield’s.com

I’ve got about 40 or so 2 year old seedlings. They’ve all dropped their leaves for the season. Pm me if you’re interested.