Here's the problem with security cameras. Someone can just cut the cable that runs to the recorder. (Which, besides convenience of installation, I presume you want to avoid.) So, installers tend to mount such cameras out of reach, and also in such a way that the cable is buried and can't be reached.
Now, if you don't want the cable to get cut, then you might think that a wireless system will guarantee operation. But while wired cameras have to be reached in order to disrupt them, all you need to disrupt a wireless camera is a frequency jammer. Just a cheap, simple broadband white noise generator of sufficient power to transmit 100 feet or so. Now you don't have to climb nothing, you don't have to cut nothing, you don't have to access nothing. Just walk around normally, doing your nefarious job, and jamming the crap out of the transmitter.
So, I didn't actually give you an answer to your question. You can do an online search for "Spy Shop" and get all kinds of returns for surveillance equipment, wired and wireless, but I wanted to point out that, if security is your real issue, wireless is NOT the way to go.