I think you're out of luck for a good view of fireworks from a moderate resort.
For what it's worth, I personally rate the Caribbean Beach Resort the best of the "Moderates". That's based on my love of anything "tropical" though......plus it's location.
I've seen a lot of the fireworks (not the entire display that you can see from inside Epcot, but enough to make it fun to watch ) from the beach at Martinique, from the patio area near the pool bar, and the beach at Trinidad NORTH, all at Caribbean Beach Resort
P.S. You should also be able to see them from the main pool area itself, but since I haven't personally viewed them from there, I'm not sure!