Hey Casey! I checked and noticed that the Twister quark does actually include the right dependencies - I think you just ran into trouble because you didn't install it. I would suggest, following Till's guidelines, that you remove anything you added to the SCClassLibrary folder. From there, you can install the Twister quark the recommended way by running:
This should install all the required dependencies - from there, you'll just need to recompile via Language -> Recompile Class Library.
Modality Toolkit might be worth looking at as well - the Twister quark provides a fairly deep and extensive set of controls for the Twister specifically. You can do a lot with it, but it's a little heavy-weight - Modality is probably a better choice if the goal is just using it as a quick-and-dirty MIDI controller. If you have any other questions, though, feel free to ask!