Be warned. those LED strips dont last very long before LEDs start dropping out, they are very cheaply made and very chinese. So, To prolong the life extraordinarily, do not run them at max voltage which is 12v, Dial it down a bit. How? A simple 555 timer based MOSFET PWM control will work just dandy for this application. For bonus points, you can make the circuit also accept external PWM control from the mac's brightness signal. (assuming your retrofitting a 5126)
You can buy 5 meter rolls of LED strips on ebay, various colors various sizes dirt cheap. Again, chinese.