Hi and welcome to the forum
What controller are you using? For a robot like this, if possible you would want some sort of computer onboard to do all the power-hungry stuff, such as processing the camera.
If you use a windows computer, I would suggest Visual BASIC .NET, as it is very easy to learn and quite powerful.
As for the duration required, that depends on how good your coding is
I would say (Anyone else feel free to correct me here), probably a few weeks of coding, followed by about a week or two of fine tuning and bug fixing.