After running a few googles for it, I'd say the outlook for finding any existing tablature (or apparently even basic chord structure) for "August" seems pretty bleak. If you ever do, please post it. I would say I'll try to figure it out, but then I'd probably bog down with it for at least a fortnight, and then find my tab-writing abilities too lacking to set it down! ...but not to be a doomsayer, Good Luck!!