Fellowship of the Ring
The Celebrían's Stone should definitely go to Aragorn to buy the spirit cards and to improve her willpower a lot.
As the two heroes can ready themselves under certain conditions, they are still able to help in combat. With some complement like Sword of Númenor for Aragorn and Hobbit Cloak and Dagger of Westernesse for Sam Gamgee are even better.
Working with Unexpected Courage will also help a lot to put Gimli or/and Merry to help with willpower.