I can't remember the brand but in supercheap in the windscreen section if you search on the little lcd index thing they have there for Corolla GTS (not that far removed from an AE86) then they list some replacement wipers.
Or you could get some reasonable wipers of a wreck and get them pouder coated!
u should be able to go to them autocheep or superbarn stores and just take a wiper off and ask them to find a match for it mate - they are pretty helpful !