Have you tried requesting from graphic shops here in AFF? Most of the ones I know are busy at the moment. But there are a lot out there. Just go through the fics under the "graphic" or "poster" tags. Or view your story under your stories tab, press the 'Make Request' button which is after the 'Save Story' button and place there what you need. And wait for a graphic artist to pick up your request. Though I am not sure if anyone picks up requests these days. Most have their own shop.

Hope you find one :)

GAAHHH i'm sooooo sorrie authornim i wish i could help but i also dunno how to do the poster im soooo sorrie a million sorrie!!! T_T *Bowing deeply continuasly*