It's great that you're excited about this, but I'm a little uncomfortable with your looking to deliberately find minis just because. As the Mini page on the wiki says:

The creation of new mini types is reserved for either a) the creator of the OFU in that continuum, or b) if there is no OFU, the first person to write about them in a mission to that continuum. The reason for this is that, while it's fun to dream up mini types, it isn't fair to the people actually writing in a new continuum if the perks of doing so are gone when they get there.

You should be writing missions because you can make something entertaining out of the original badfic, not out of some desire to "catch 'em all."