Just thought I'd mention for you guys who might be building beatmania panels, or who might want to play beatmania on a panel you're building... I built my panel with a pretty standard 6-button fighter layout, three buttons placed straight above three others. Then I installed the beatmania clone game, and I'm wishing I had offset the top row to the right a little bit. The top buttons being straight above the bottom buttons makes it very confusing and very difficult to have two black keys in between the three white keys, which is a setup you really need to pass lots of songs. It gets really confusing for me which button is which, because the top buttons aren't in between the bottom ones like they are on a piano.
So, if you wanna play beatmania songs, you might want to set your top three buttons a little bit off to one side.