Hi
kpdf uses the xpdf settings to determine fonts and xpdf gets its settings from a file named xpdfrc. type 'man xpdfrc' to obtain font related settings. Specifically see the option "displayFontTT". Also see the example at the end of manpage. Unfortunately there is no gui to set these things u have to edit the file xpdfrc manually and set the desired fonts.
Hope this helps.