I think Cisco is dropping the use of HP servers and putting 7.1 on their own servers from now on. 7.1 will be supported for quite some time.
Basically, in your PUT tool online, order everything you need for each node. The numbers are probably wrong online and say some odd number like 23 units, when you have (4) nodes. so just order 1 for each server and then one server license for the upgrade.
Are you ordering new hardware as well?
As for the device licenses, you are grandfathered in with what you have on CUCM 4.x. So if you have 500 7060 phones, then you will get DLUs to cover this (no cost as long as your smartnet is current with 4.x and phones) Same for your cucm nodes.