If you have a Pandora store near you, they sell the Disney charms as well. They normally have all 25 non park exclusives in stock. This is what I did before we went in December. Bought two non exclusive charms as a surprise for my gf, then when we got to the park I got her the bracelet and AK exclusive charm.
I think a lot of people overlook the Pandora stores and their website and just focus on either DisneyStore or the actual parks.
But if you're going mainly for park exclusives, good luck. We go about once every 1-2 months and the best spot we've found for the charms is uptown jewellers in MK. Normally they have a good amount of park exclusives in stock as they seem to get shipments in frequently, and there's generally not a line.
However as far as DTD. We checked there once and then decided to leave once we saw there was about 20-30 people in line. I'm sure it's not always like that, but Uptown Jewellers would be my first stop