I had no idea this could be done! While browsing Youtube for videos on the Vaio SB series, I came across newmodeus. Ordered a caddy and installed the hard drive in a matter of minutes! This is great! Even came with a black pouch to put my optical drive that was removed from the laptop.
Couldn't be happier!
2nd HDD / SSD caddy Sony VAIO SA, SA3, SA4, SB Series (White)