Petit Billy chevre, which has a rounded flavor, is ideal for the filling, but any mild goat cheese will work.
as spring arrives here in the northeast, I would suggest using mint that grows wild in your backyard or neighbor's garden. This has a fresh flavor as opposed to spearmint flavor
There are many varieties of mint. I strongly suggest you try a leaf or two of your markets offerings before making this dish so you can choose which flavor is best for you. If you're not a fan of mint, tarragon or even flat leaf parsley will work.