http://canopus.iacp.dvo.ru/~panov/cm-unicode/

Then I messed around a bunch with the advanced options on the Font Squirrel @font-face generator:

http://www.fontsquirrel.com/fontface/generator

I don't remember the exact settings I used, but it needed a decent amount of tweaking to end up looking acceptable.

The base64 encoding doesn't contribute to anything other than website performance. It saves an additional request in modern browsers. The other linked fonts are for IE/Older browsers.