If you intend to go all the way to PDF, you will probably want to use PostScript fonts exclusively, since the Adobe PDF readers are extremely slow when dealing with bitmap fonts. Commercial versions of the Computer Modern fonts are available from Blue Sky; public domain versions are available from CTAN sites (for CTAN info, see section `unixtex.ftp' in Kpathsea) in:
fonts/postscript/bakoma fonts/postscript/paradissa
You may need to modify these fonts; see @url{http://xxx.lanl.gov/faq/bakoma.html}.
Also, the Adobe distillers prior to 2.1 drop trailing space characters
(character code 32) from strings. Unfortunately, the PostScript fonts
use this character code for characters other than space (notably the
Greek letter psi in the Symbol font), and so these characters are
dropped. This bug is fixed in version 2.1.
If you can't upgrade, One workaround is to change all the trailing
blanks in strings to a character code that isn't in the font. This works
because the default behavior is to substitute a blank for a missing
character, i.e., the distiller is fooled into substituting the right
character. For instance, with the Blue Sky fonts, you can globally
replace ` )' with `\200)' (with sed, for example) and
get the desired result. With the public domain fonts, you will probably
have to use a character code in the range 128 to 191 since these fonts
duplicate the first 32 characters starting at 192 to avoid MS-DOS
problems.