Question about Sata III

The cables that came with your motherboard should be okay.

Acoording to the Internationally adopted standard, there is no difference between SATA 2.0 and SATA 3.0 cables. The cables are the same. The pin-outs are identical.
The cables are interchangeable. Consider advertising claiming SATA 3.0 cables as a sales gimmick.

Sometimes there are low quality cables that cause problems. They can be advertised as either SATA 2.0 or SATA 3.0 cables. A few manufacturers may have poor quality control. A few manufacturers may take short cuts to reduce manufacturing costs.

As Johnny stated, you are fine. The only time you have to get Sata III is for some external enclousers - They key the end that plugs into the encluser so that you can not use Sata II cables..

As to hdmi cables, just as I shy away from overpriced ones, I also do NOT get the elcheapo ones. The same can be said for sata II/III cables. Ones supplied by MB venders normally fall in the Mid -> above average quality.