On a new build I Install the cables ( for short runs the video coax need not be super duper quality) and leave tails hanging out of the wall ( or roof ) An exterior dome will do the job, or one of the day/night types with the infra red leds will give you black and white images in the dark.
There are so many cameras about that advice is very difficult to give.
The more you pay the better you get IMHO.
does that mean I a junction box outside, I want to make it look neat and tidy, just the camera if possible (do the cameras come with a length of cable already attached?)
thanks for your time and input
Dome cameras have the connections inside the dome as a general rule and are mounted so the wires enter the base of the unit so are not visible at all once the top is on.
Other types of weatherproof cameras have two leads ( power and video ) coming out of the casing and have plugs/sockets for connections.
A search on any of the Internet auction sites for CCTV cameras will produce dozens of results.