Hehe, I also am in the same position as you two, and need a mixer with as many as possible aux sends (for using fx units).
After doing some research and reading lots of reviews, what stayed on top of my list (I have not fully decided yet) was the Mackie 1642 VLZ3 for ~500EUR, which is a lot of money, but will be sufficient as your midibox machine park grows :).
Also, it offers quite good value for the money, lots of channels, quite compact design, the equalizer section is very good, has 4 aux sends, very decent overall sound quality...
16 channels may sound like overkill, but when you have a MB-6582, you have 8 input channels alone (if you do not passively mix them together), add one or two stereo synths and one or two fx machines and you need them all...
Greets!