The challenge in picking an amateur radio transceiver to use in your vehicle is deciding what bands you want to talk on. Since I do storm spotting and public service work, HF mobile doesn't hold great interest for me. I've focused my set-up on VHF/UHF amateur bands plus APRS. Your needs may be entirely different.
As for the other items, a scanner would seem to be a must, but the choice depends on what type of scanner you need for your area.
What do you plan to switch with the switches in the switch bank? Think those needs out very carefully.
As for CB, I've listened a few times while on trips, but I just don't feel that it's worth the bother. Depending on your scanner choice, you may get adequate CB receive capability with the scanner. Or, if you decide to go with an HF amateur radio, you'll also get CB receive capability. But, if you plan to talk on CB, you'll have to make room for a dedicated CB radio if you plan to stay legal.