Just use industrial velcro to attach the control to the Sub box.....
as for the satelite speakers.........
get two small 4" pieces of 1" right angle aluminum....velcro or screww it to the bottom back end of the satelite speaker forked feet... with the angle facing down........then simply insert the part facing down INTO the MUSIC HOLDER SLOT ....instant speaker mounts!!!
Sub on the floor.

Carry the z2200 in a small canvas duffle bag....at the gig just unzip, drop the sides down, and put the satelites in the Groove on the KB and play!