Hmm, I would need to have a look at this the next time I play CIS. Their fighters in general are pretty weak but have large numbers, but the Rogue-class and Belballub-22 should be effective at all levels. Outside of that the Geonosian Cruiser has an anti-fighter laser weapon, while the Recusant, Sabaoth and Trireme have flak cannons.

I would yeah, recommend the Trireme corvettes for anti-fighter duty.