Wiring GFCI/Switch Combo
Given that you are splitting power to disposal and dishwasher, you cannot "split" and have some things be GFCI and others not.  You have to put the works on GFCI, which will be annoying. 

Putting the GFCI under the sink in a 2-gang box is out of the question; the reason is GFCIs must be accessible.   Your options are:

GFCI breaker. And done.

Or:

Put the entire downline on the GFCI+recep+switch

...including the switch itself. 

Pretty simple to wire:  The hot and neutral from supply go on the LINE terminals. Nothing else goes on the LINE terminals.  All other things go on LOAD, no matter what (except grounds, of course).  Pigtail if necessary.