I've had a go at bashing together a comparative chart of maximum service ceilings (m) for the various aircraft deployed in the Alto Cenepa conflict.
I've divided this up into bands based on the four altitude levels used in the Wings at War rules system. This seems to work although it does mean all helicopters are restricted to a maximum height of Level 1. This matches with the maximum height for helos in Flames Above the Falklands, MiG Alley and so on, so that seems fine. It does mean that they will have to fly around any hills which should make resupply and ground attack missions that extra bit more interesting.
These results seem to give a good balance between the two sides as well, so I'm proposing that I take them forward into the first draft of the modified rules.