you could use a Manufacturing output function.... configure it and generate several types of output data ;-)
(don't know how it is licensed - which features)
The only way you can get all the output together is by Editing the layer .
I mean to say that you need to add different layer in one single gerber file and assigned the information needed in specific layer for that Gerber File .
Remove all the layers you do not need .Select a particular layer for e.g say Silkscreen layer and the add all the other layers you need in a particular Gerber File.
This solves the problem .