Don't worry about aesthetics at this point. Keep in mind that you're going to want to go through numerous builds on MG before committing to the actual device. Also, using an overly-large cab in your MG build will help in that you can overbuild, then pare things down to something approximating your final result. But again...expect to do that a number of times before you start spending.
Anyway, by "inputting pitched sequences" do you mean that you want to play notes in and have them recorded as a sequence, or are you talking about more typical sequencer usage?