thanks for all the advice and recommendations, everyone.
Slim, I realised your advice to go more HP. I bought another 6U Rackbrute case. I figure I can connect the twin rackbrutes and still be reasonably portable.
Im still in the market for a mixing solution, although my 'wants' from the mixer have evolved - here they are
*effect sends
* six channels or more
* cv control / vca functionality
* stereo panning from mono input
* HP is less important than value
Cheers