Since you plan to use the 2200's to drive your Mini's, you would want to move the left and right channel cables from the 7500 to the 2200's (both for the balanced cables from the 990 and for the speaker cables). The 7500 can remain unchanged otherwise, or if you have a 7.1 setup you could move the other set of surrounds onto the left/right channels of the 7500.

As for the triggers, I can think of two reasonable approaches. You could let the 2200's auto-detect a signal, in which case you wouldn't need trigger cables. You could also daisy-chain trigger 2 from the 990 to one amp and then to the other amp, in which case you would need to set the "Trigger 2" control to "On" for each of the 990's inputs so the amps come on.