https://www.overclockers.co.uk/akas...ith-securing-latches-30cm-blue-cb-075-ak.html
This is an example of a SATA data cable you can order from a UK vendor. Overclockers.co.uk are very good, I'm on their forums.
There are various different SATA cables in various colors, braided, not braided, purple, white, etc etc etc.
There are also some SATA cables that have a straight end and a right angle end. In some computer cases where the SATA data and power connections are close to the case, be it the drive cage or a side panel etc, you will need to use the right angled end on the drive itself.
Most cheap motherboards come with 2 SATA data cables and high end motherboards can come with 4 SATA data cables (or more). If you look up your particular motherboard you should be able to figure out what exactly the package contents are. You should also look into the specifications of your case. Motherboard only comes with straight end cables and you need right angle? Order appropriate cables. Have 3 drives but mobo only comes with 2 cables? Buy another one. etc etc.
It's always good to look into stuff beforehand to be prepared so you don't find yourself met with unpleasant surprises when you build the machine.
Also, there are SATA II and SATA III aka SATA 3Gbps and SATA 6Gbps cables on the market. Buy the SATA 3/SATA 6Gbps cables. Some people say there's a difference, some don't... I've heard better insulation, better conductors, etc. I have no idea if it's true. Yes, a SATA 3 drive will work with a SATA 2 cable, but with prices being identical, why not buy the SATA III cable, know what I mean?