you can get it at skill 28 or 38 i dun remember but its not really worth the 10k GP that you have to pay fer it with now thats theres a alchemy guild in Aht aurgan so u can just get ur image support there or still in bastok.
The guild belts that came out are indeed a charge holder for Synthasis Support, with the exception of Fishing which is Fishing Support. Great to have if you craft out in the field in exp parties and the like, but still, Im not one to really use it ^^; I already explained why on the Bonecrafter's Belt, even tho i have it, Mine's for show hehe