There is no appearance tab in my Safari preferences.
They killed off the appearance feature in Safari 2 or 3 years ago. Are you using Version 8.0.3 (10600.3.18)? Your post sent me scurrying and I remembered the old friend Tinkertool, sure enough it let me set the font which I did not know was possible. My freeper page is now happy. I am running the latest version of everything, always have.
Looks like I'm way behind. The screenshot was of Safari 5.1.10 on Mac OS 10.6.8. Probably time to think about a new machine.
On the other hand, the fact that they got rid of the ability to change the font without using Tinkertool or defaults write or writing a user style sheet or similar raises the question of how many other such regressions may exist. Sheesh! Maybe it's time to switch to Linux.