gouramis are from asia so they should also go. no angels or congo tetras. you should add to the school of harlequin rasboras (they arent tetras) as they do best in schools of 10-12. cardinals would be great but you would need a school of at least 6, not just a few. the temp shold be at 86 for discus
1: it really doesnt matter where the fish are from as long as theyr compatible
2: despite what many people say, i know from experience angels are fine with discus, tho small angels are very fragile, so i dont know if theyll make it with you r particular discus who seems very aggressive, if you want some youll have to get them at a decent size.
3: discus do not need a temp of 86, tho they prefer no lower than 80. i kept my tank at 82 and they were fine.