Hi, I'm Bhavik. Welcome to JustAnswer. I'm reviewing your question now, and will reply back ASAP.
I am opting out,as I could not find sufficient information on this for you.
All of your plugins are available from the Sweetwater Web site at http://www.sweetwater.com/shop/computer-audio/software_plugins/ . You can select plugins for all manner of virtual instruments. I could use a bit more explanation of the following point: if you have a mixer, why are you necessarily interested in pre-amplifying one or more inputs? Rather than pre-amplifying inputs A and B and passing through C, D, and E unamplified (for the sake of example), I would recommend just accepting A and B directly and attenuating C, D, and E, all in the mixer. relying upon a separate amp stage closer to the output to provide the final gain.