Thank you all for your replies. I have read this morning that the Sabertooth can be connected directly to a PC through serial (usb to serial, no need for max232 to level the voltages). I will try to get those first working with a laptop, just to get the hang of it, and then work my way from there to add arduino microcontroller and IR sensors.
My master's thesis was about autonomous navigation using a single camera. For this, am planning to add 2 camera's and use them as stereo. anyway plans for the future, i will be happy now to get everything working from a netbook (that will cover wifi and cam connections).
what do you suggest as arduino kits? to interface with sabertooth, pc (usb preferred, serial is ok too) and the rest of arduino sensors? is there anything i should keep my eye on when choosing boards?