Pie Lady, you should consider picking up a copy of Marshmallow Madness
if you haven't seen it. Amazon has it for only $10.21 right now.
I ordered it a few weeks ago, and have been happy with the 2 batches I've made from recipes in the book thus far (peanut butter-banana-bacon, and sea salt caramel swirl). Recipes vary from flavoring with fresh or frozen fruit puree, to fruit juice, to alcohol, to malted milk powder, to root beer, to kool-aid or similar mixes, and so on... The recipes generally look good, and they certainly provide a good idea of the proper ratios of various ingredients to go on and try your own variants.