There is not any kind of overview of merch unfortunately - there is simply too much of it and even now the occasional new item still pops up. If you check out Ivy's website, ponylandtours.com and search for individual ponies you can find different merch for different ponies. That and ponylandpress have some good merch images.
As for your Medley list - what was on it? Do you just mean a list of all the Medley's released or something more detailed?