I've killed Naggy many, many times. He's easily single-groupable, without uber gear or veteran rewards AAs. The last time we did him our tank was a 52 Gnome Paladin in Clockwork Observer armor, which isn't all that great. She did have a good weapon, though (Fabled Razing Sword of Skarlon). We also had two clerics, a bard, and two rogues. None of us had raid-level gear. The resist song from the bard was essential or we would have wiped - with it, Naggy was dead before the third cheal was needed on the tank.
Vox, however, is much harder. I've yet to see her corpse.