I guess the right hand buttons are mostly unused for every right handed player so it's the six left hand buttons on the base that you need to map, plus of course the ones on the stick.
On the top I have both guns on the trigger, zoom and clipboard on the sides and look front up in the center. The hat is obviously for the views.
On my list of most used features I'd put on the base if I hadn't them on the throttle are: voice buttons for squad and range, look upand wep. That would leave two buttons for features like weapon change and secondary weapon for bomb and rocket use.