Hello
I think that most important for Arabic font is [King Fahd Complex for the Printing of the Holy Quran] group fonts ( it's 3 fonts)
they are the most specialist in Arabic world and their font is accepted in all Arabian world
and they write the Holy Scriptures with it and the Arab government use it
we think that will improve also the search engine in Google when they use this font in their database for search also
and will improve Web
and all is Opensource and unicode
the links can see in
1
the Quran font by Saudi gov that specialist in that
2
regular arabic writing all letters
and same but bold
3
additional font for titles
thank u