Actually, the next step of Tie Advanced research gave birth to TIE DEFENDER (Defender of the Empire, an addon for TIE FIGHTER, ). With three solar panels, now those guys were truly unstoppable, but I don't think they were ever "official" Lucas material. Speaking of which........there's also the Tie Phantom, a cloaked Tie fighter with 3 ventral fin like pannels....wicked!
OK....now more techno info on the Tie Family than you wanted to know.