theres a retrimming place in mclaren vale that do a really good job and gove you the option of having things embroied into your seat at no extra cost (well they did for my mate) they do boats, cars whatever really but over all not a bad job.
price youd be looking between 1-2k depending on whats getting retrimmed and in what matrial etc.
as for airbrushing, i only know of one person in SA (doesnt mean theres only one though) his shop is called petes killa customs i think. dont know the number or anyhting just know his work.
cheers
oh and if petes isnt open try giving m&c doyles a call and talk to mike, im sure he would know someone