Real has Ishod Twin Tail shapes in 8, 8.25 and 8.3. None are in the current catalog, but were made this spring. Tough to find.
Creature has their EVILLIVE shapes in three sizes. Not easy to find either, but Zumiez (i know... shitty) has an 8.5 one in stock.
Street Plant has twin shapes occasionally, but they seem to be more like twin-nose instead of twin-tails.