To answer the question at hand, I'd say Lakers. I like the matchups we have with them, and have had proven success against nearly the same lineup in the finals.
While I would normally think Phoenix would be easier due to their subpar defense, I thought the same thing in the regular season until the Suns came to Boston and ran the Celtics off the court. The Celtics haven't faired well against running up-tempo teams, or extremely athletic teams, and I think the Suns would be very difficult to beat b/c of that. Notice how the Magic do well when they run? The Suns are a far more effective team in the up-tempo pace.