Larry has a 2009 27" iMac and is looking to add an SSD into it to create a kind of Fusion drive. Leo says it's tricky to roll your own fusion drive, but it's possible. Macsales.com is a great source. They have videos on how to make one. iFixIt.com is another source. But why do that when he can just get the largest SSD he can and then save his data on a secondary spinning drive?
Is Time Machine a good backup? Leo says it works, but he prefers SuperDuper because he can make his external drive bootable and it will enable him to boot to it immediately if the internal drive goes down.