There are plenty of font editors that let you modify existing truetype fonts and generate new ones from them.
I haven't played with fonts since the Win95 era but I remember one app that let you convert a regular font to slanted, outline, and several levels of boldness with just a click.
(Don't even remember the name, much less where I stashed the Floppies.)
You might want to try a web search...
Edit: Something like this MAC application:
http://glyphsapp.com/