CMOS, is a type of chip found in some video cameras, as opposed to the more prevalent CCD chips. Rolling Shutter is an image artifact caused by a CMOS chip reading from top to bottom as opposed to globally as CCD chips to. Meaning, that certain events which are VERY fast (Flashes or VERY fast action) will bend/warp or only register on part of the image, as it was only recorded by part of the chip.
CMOS cameras, in my opinion yield a very nice picture, I in fact own a CMOS PMW-EX1 from Sony, but I would NOT recommend them for work where there will be a lot of flash photography happening.... e.g. a wedding.
All of these concepts are better explained on sites such as wikipedia for types of imagers, and googling either CMOS or Rolling Shutter Effect will show you many video results.
You'll have to look over whatever camera you are considering and on bh's site, at least, under the specifications tab, such as this from a canon camera :
3 1/3" Native 16:9 CCDs at 14http://www.bhphotovi...#specifications
You'll have to look around to a camera which fits you specific needs, but you'll want 3 CCD, probably HDV, tape based, a lot of batteries, good tripod, as well as some tapes. I would price you around 6000 or so for a nice set up including audio which will work for weddings as well (on camera mounted, extra stuff you never account for etc).