IMHO, the one that's close by and has tons of Disney stuff is the one at Orlando Factory Outlets. (Just down the street from Dolly Parton's Dixie Stampede). I have to admit I wasnt looking for pins at the time I was in there so, I can't say for sure the quanity they have. It's a really great store for discounted disney stuff.
That being said, the one in Lake Buena Vista Outlets (off of 535) barely has any Disney merchandise at all. They throw in powerpuff girls, scooby-doo, barbie, and various other Universal characters. My advice would be to head over to the factory outlets.