For me, a desktop controller makes more sense - it seems that
it would be quite difficult to play an instrument in a rack mounted
position! RE: layout, either would work for me, but as pointed
out, a KB configuration might make playing it easier. The big
question for me is - what type of power supply I don't have any
more rack space (for a bus connection), but was wondering if the
TKB may be mains supplied (or maybe a - YUK! - wall-wart).

-andrew bunny