Virgil,
I have never seen 10KV rated cable. It usually goes 5, 8 then 15KV. 8KV would work but it seems the manufacturers don't offer it in JCN. Rome cable has shut down all their warehousing and distribution. To get cable from them these days they make it when you order it. That means unless some supplier has it on the shelf you'll need to order 10,000ft. Try Southwiwre, Okonite, Kerite, General Cable or Perelli.
Allot of high voltage contractors use 15KV cable and components on 5KV systems because they can be a little sloppier on the terminations and get away with it. Same would hold true with your 7200V system. I don't know how excited someone is going to be about traveling long distances for two terminations so your better off finding someone local. I would have to agree with Bob that if there not done right they won't last very long.
Keep us updated and send some pictures if you can.
