Remember Prince Thrakhath's flagship in the Wing Commander 2 intro? A lot of fans remember the majestic KIS Hha'ifra from its brief cutscene appearances, but quite a few assume it's just another Ralatha. It's actually a fearsome Rigakh class cruiser however! LOAF whipped up a couple top/bottom shots to illustrate some of the unique aspects of each ship. The engine nacelles on the larger Rigakh are more like a Fralthra's, and the Ralatha has fewer of them. The Rigakh also appears to have a large bay opening in its nose.Marc has posed the Rigakh and Ralatha next to a Fralthra and Kamekh.
I don't have the original to render out, but here is the Rigakh (of course, not to scale).