Take a look at MDPC. They have some amazing stuff there. And they have sleeving specifically for Sata cables.
http://en.mdpc-x.com/
If you check here:
http://www.xtremesystems.org/forums/...d.php?t=202639
you'll see that a lot of people are using it. Supposed to be the best. I have not bought any yet but I will be soon.
In terms of the amount needed, measure the length of one wire, multiply by the number of wires you are going to do and then add about 20% for off cuts and oops moments.
Hope this helps.

