I have been tinkering with wireless cameras a little recently. I just got my technician's class amateur radio license last weekend, so I'm now legal - which is something to keep in mind if you are planning on building your own wireless transmitter. My plan is top take real-time video from R/C airplanes so I need a small, very light-weight, low power camera and transmitter..
As far as cameras, I have two suggestions - the first is to go onto ebay and search for "pinhole camera". They sell some wireless setups for about $60 shipped. You could use the camera portion of it as the imager and the transmitter is a pretty straightforward circuit that might be recyclable - although they are 900MHz as I recall. Otherwise, I would highly recommend using a CMOS imager instead of a CCD simply to make life easier on yourself. CMOS imagers usually are more easily integrated into a hobby-grade system.
As far as the 802.11b controller, a couple of companies sell single-chip solutions. Atmel is one that I definitely know has a complete solution in a chip. It can be very hard to buy a single chip from a company that normally deals with high volumes though. Your best bet is to call them up and keep asking for customer samples. Then I'd explain your situation and ask if they'd be willing to ship you a single sample for your project, or know of a place that will sell you just one. A
link to Atmel's offerings.
As a veteran of several of these types of projects - I would say that you are in for quite a bit of work. My project is vastly easier - basically to adapt a 900MHz NTSC analog video camera to have substantially higher power capable of increasing the range to over 1000ft. I wouldn't even want to consider doing what you are talking about doing just due to the complexity of it.