I bought my Coker Firestone 21" tires from Summit Racing. Same retail price as most $159, but free FedEx shipping. They were worth every penny as the ride has improved significantly over my 40+ year old Allstates. Tires were on site in 72 hours.
No mention of radials? but so far they not only appear to have better wear characteristics than cross plies, but they have made the steering lighter and the ride a little better. Only disadvantage is price?
I can't understand why radial tyres would require different tubes? I certainly run our radials with the same tubes that I had in the original tyres without problems