Thels
First Post
The PrC's found in the 3.5 DMG are those listed by Mithreander and the Red Wizard of Thay. Since going by the SRD was already decided earlier, that makes things simple, he's out 
IMHO, the Red Wizard is included more as an example for creating realmrelated PrC's than as a usefull PrC in generic DnD. It also has requirements that aren't available in generic DnD, like Tattoo Magic.
Anyhow, since LEW is all about custom player options, Janos could come up with his own order of evil magi. I wouldn't call them Red Wizards though. Using Red Wizards will get too restrictive as a lot of stuff is attached to them (including opposing PrC's etc...).
As for Paladins and Evil, that's something debatable too. IMHO, characters don't radiate evil just because their alignment is evil. They actually have had done an obvious evil act in the past in order to be detectable by abilities such as 'detect evil'. This way, paladins could travel around with characters with evil alignments, but if those characters start killing people without reason, animate dead without authorization, etc..., they are clearly evil, and paladins can no longer accompany them. Exception: Clerics worshipping an evil god and Blackguards attain an Aura of Evil right away, so they're clearly evil.

IMHO, the Red Wizard is included more as an example for creating realmrelated PrC's than as a usefull PrC in generic DnD. It also has requirements that aren't available in generic DnD, like Tattoo Magic.
Anyhow, since LEW is all about custom player options, Janos could come up with his own order of evil magi. I wouldn't call them Red Wizards though. Using Red Wizards will get too restrictive as a lot of stuff is attached to them (including opposing PrC's etc...).
As for Paladins and Evil, that's something debatable too. IMHO, characters don't radiate evil just because their alignment is evil. They actually have had done an obvious evil act in the past in order to be detectable by abilities such as 'detect evil'. This way, paladins could travel around with characters with evil alignments, but if those characters start killing people without reason, animate dead without authorization, etc..., they are clearly evil, and paladins can no longer accompany them. Exception: Clerics worshipping an evil god and Blackguards attain an Aura of Evil right away, so they're clearly evil.