I'd suggest utilizing Conjuration and Transmutation for BFC and DD. Conjuration is my favorite school and remains versatile and useful at all levels. Transmutation is a close second. When making a specialist, I never consider dropping either of these. You lose so much when you do.
AFB now, but don't you have to drop at least one school to be a red wizard? I can't remember if you have to be a specialist too (total of three dropped schools). Assuming I'm right:
Evocation is actually a pretty easy school to drop, especially with you having access to CArc (the orb spells). Really, about all you lose from Evocation is Shatter, Wall of Force, and Contingency. Shadow Evocation and it's Greater cousin can make those up nicely (assuming you didn't drop Illusion).
Dropping Enchantment is pretty easy too. There are several nice aspects you lose out on, such as controlling other people, but the heart and sole of Enchantment is Will-save-or-lose. You can do that with Conjuration, and you can do it without the nasty [MIND AFFECTING] tag attached. Illusion and Necromancy can also help you out here. Enchantment is one of the most redundant schools in combat situations. If the game is heavy, heavy RP-based, then you might want to rethink this choice (depending on if the DM allows magic to win the RP mini-game).
Other choices for dropping schools would be Abjuration, Illusion, and Necromancy. This is where it gets tougher. Abjuration has some really useful spells, especially the Dispel Magic line. Illusion can be very versatile, and can make up for Evocation with a mere two spells. Necromancy has some wonderful debuffs, like giving people negative levels (and massive save penalties) with a touch attack (spell resistance does apply, however)! Given these three, I'm most likely to give up Necromancy unless specific circumstances dictate otherwise.