I recently had a few *.eps documents sent to me that don't render in the correct fonts. Two of the documents have the fonts embedded, which is great so they render properly.

The other two didn't embed the fonts, which are supposed to match the font in the logo graphics. The two fonts are "Lithos Pro" and "Michelangelo BQ".

Other than just looking one by one through whatever free font families I can find, is there some website that I can search for similar free fonts that will render close to the same?

Or do I just have to buckle down and purchase the appropriate fonts if I want to use them (assuming of course that they can be installed to a linux machine - I've never really messed with font families before).

http://www.identifont.com/find?font=lithos+pro&q=Go

Looks like those fonts are supplied with some Adobe software. It's unlikely that a different font will match the same height and spacing in a specialized use like a logo. The site above does list similar fonts.

Best bets for Linux support are True Type fonts (.ttf) and Open Type fonts (.otf). Other formats may not display or print properly.