I do agree the font size is way too small, but I don't think pixels are a bad idea in most cases.
800x600 and 1024x768 have almost 90% of the resolution market...
There are very few that have their resolution over 1024, but if they are, they certainly aren't at 1600x1200. Now this is for most people, there will be exceptions.
This will always differ depending on your target audience as well.
So, I do think your font size is too small, but I don't think you have to shy away from pixels.
stolzyboy