Stepsequencing like CNTRL:R

hey guys,

i´m building a quiet fantastic custom controller at the moment, based on 2x brainv2, containing 50-60 pushbuttons and around 20 encoders.
2 blocks of the pushbuttons should work as stepsequenced drum-grids. actually i´ll have a 4x4 and a 16x2 grid for that.

questions (and sorry, i´m a bloody beginner):
- where can i find general info for programming that?
- which max4live stepsequencer might be best for that?

i´ll have millions more questions as soon as i have the controller in my hands, these 2 are just to learn and understand it, to get it done quickly when the controller is finally built in about 3 weeks from now.

i´m attaching a screenshoot of the frontpanel to give you an idea what this thing will be like.

thanks a lot

s