I was seraching for a way to tyoe farsi directly in to after and I found your post
i am from Ian and I think I can help you
you gonna need Photoshop ME (Middle Eastern) version and you can type farsi directly in it and also there is ME version for most of adobe apps specialy for design apps.
here in Iran we use an application named : Maryam and it is easy to find and so cheap about 15$
i can post it for you if you like and otherwise you can find photoshop ME and you can find more Farsi Fonts at irmug website and many more on internet if you search for it but Maryam is windows only so you have to do the 1st one on a Mac i use apple too but you gonna need a windows if you like to do Farsi stuff easily
nice to POST you and if it is too late I’m sorry
thanks
OSA
O.S.A