Despite the increased cost to launch a Phase 3E class spacecraft into a GTO type orbit it would seem a multitude of launchers are possibilities such as:
1. Molniya 8K78 launch vehicles from Plesetsk and Baikonur. I believe several dozens of Molniya 1, 2, and 3 series have been launch since 1965. This launch would be ideal and no propulsive component would be needed.
2. China’s Long March
3. India’s GSLV
4. Japan’s H-IIA
5. Space-X Falcon 9
6. Ariane 5 ME debut 2018
Also, what happen to the rideshare option?