Nigel, welcome to the forum.
I have a EVO 840 500 GB SSD. It is one of the best drives I have ever had. Samsung has good software to help you migrate your data and maximize performance once the drives are installed.
Here is a SSD adapter bracket that may work for you. Here is a guide that may help you with the installation.
Please click the Thumbs up + button if I have helped you and click Accept as Solution if your problem is solved.