no more channels as CB is limited to only 40, reception and programming options and layout are going to be the difference in the units, no FCC certified CB is going to give you more than 4watts of pep (peak output power), so even if the box says it has 10 watts, it's only going to be putting out 4 on transmit,unless it says SSB capable.... on another note you can have a look around for a unit that has the option for SSB, using this you can output 12 watts instead of 4 but requires a but more understanding of usage.
here's a good page that shows what each channel is used for, you can see that the maritime radio's operate on different channel, unless you planning on modifying you radio i wouldn't use a maritime radio for your rig , both of which are highly illegal and you have a bunch of retired engineer nerds who drive around and try to bust people doing this sort of thing....
again with these sort of things it's an entire system, it's the radio,the antenna,the cabling and the placement of it all, unless you know what your doing i would really just go with what's tried and tested and follow one of the set-ups someone else on here has and reports that it works well.
i personally was disappointed with the limitations of the CB and went straight to HAM seeing the need for something more robust. with ham you can actually be a one man base station, my grand setup is going to allow me to have a hand held unit and transmit from that to my car and then relay from the car to either my home or a local repeater and on out to the world from there, so in essence i'm never out of touch and have basically a limitless range depending on conditions and the rest.
complete band plan
FCC Frequency Band Plan
looking for people breaking radio laws is almost a sport for some, called fox hunting, i'm personally trying to learn this, as it can be a very handy skill.
Transmitter hunting - Wikipedia, the free encyclopedia
National/International Championship Foxhunting/ARDF News
really though i'd just get your ham license and go from there, it really is a much better system and it's not expesnive or hard to get ...well really hard to get.....
take this test
eHam.net Ham Radio Practice Exams
the Technician - (July 1, 2010 question pool)
if you pass i would just go down to a local club and pay the $15 and get your license, it's good for something stupid like 10 years and after that you just pay again no test needed.
that said, cb's do have their place, i just wouldn't invest much time or money into the system, most of what the guys have done here with the basic ash tray type units is all your going to want/needed from a cb imo, like said above me, if you want more then you really need to skip the cb and go to ham as cb is severely limited. but really though, look at your usage, if your running trails you should be in a group and your never more than a couple of hundred yards away from each other , for this a CB is more than ok. if your going solo and far out in to the ether then get the ham.
side note, in the event human life is endangered you can broadcast on any channel.