What do the units look like?
Like CB's, but cooler
What are the mounting options?
Limitless. particularly because many have detachable face plates. So you mount the main unit to the center console, under the seat, in back, etc. then the controls are mounted more conveniently to your dash, console, overhead, etc.
Does it have emrgency specific channels?
In an emergency, you're allowed to use absolutely every channel available to you, within the means of your equipment. There are several weather channels, but I don't think there's a universal "channel 9" like on CB. Mainly because of differences of coverage areas, etc., the better approach is to reach someone close to you, which is best done through a local
repeater.
A repeater is like a gateway (big network hub) for Ham radio, receives well then re-transmits to a greater area with higher power. Using a single repeater we chat all across Denver metro on Monday nights, most just using little hand helds (HT's). With no repeaters (radio to radio, aka
simplex, I've talked to guys as far north as Boulder and as far south as Parker & Highlands Ranch from on top of a hill near my house in Broomfield. From my driveway, simplex is just as good as the repeater when speaking Groucho in Arvada.
With linked repeaters, we can chat from here to Grand Junction (via Colorado Repeater Connection). Throw the internet in there (IRLP), and you can conceivably link the world.
edit: there are several install pics, including mine, in this thread:
http://forum.ih8mud.com/showthread.php?t=146532
edit2: and my comments above mainly pertain to the 2 meter band, which is the most common, easiest to be licensed for range of Ham radio. there are several others.. and when you study to pass the test you'll learn about all of them, but if what you're looking for is a "better CB" then all you need to worry about is 2m. I've had a quad band radio for almost a year and I've still only used 2m...