Yes, natively accept any font library would be really good. But it would be enough with fontello only, because fontello supports all popular web font libraries, including Font Awesome.
The thing why I love fontello.com is because I don’t need to include all of the font library icons. You select only icons you want to use from all the libraries (Font Awesome, Entypo, Typicons, Iconic, etc.). I usually select about 30-50 icons I like and fontello does the rest (generates css and other files to include in website). It also allows to upload custom svg icons to include in package. So I can really make a custom font icon package, not as usually including 1000 or something icons I will never use.
Thanks,
Janis