Batboard

I am designing a mobile system for a new truck that I am in the process of buying. I will be running 5 radios inside the truck and would like to minimzie the speaker and mic count. I am looking for anyone that has already designed a working and functional audio mixer. I am able to design one and have actually started the process, however, I know a few of you on here and also batlabs and hamsexy websites have already designed a system. I would be interested in seeing your design schematics if you would be willing to share them.

My radio set up will include the following:

pro-2096 digital trunking scanner
moto spectra for vhf
moto spectra for uhf
edacs ranger or orion for edacs systems
cb radio of some sort.

So the design but be able to handle the the audio outputs of motorola rigs as will as scanners.

Thanks for any help that anyone can give me in advance.

Dave