I think (from a D2:ED topic) the main font is CM Tiempo
, and some characters are taken from Morpheus.
The D2:ED fansite kit includes the Lombardic font in the website folder (don't know if it is used in-game at all). The FoV presskit just has logos and screenshots, and if there were updated presskits for DKS or D2:DC, I don't seem to have downloaded them, and can't find any working links in a quick search.
I thought of the font mod, as well, but it is a replacement d3d9.dll file placed in the bin folder with the game executable, so it probably just scales the font, rather than replaces it. It can't hurt to try it, though.