Apart from cheating with a hybrid, I'd do something like:
1 Focused Illusionist Shadowcraft Mage, bans Evocation, Conjuration, Abjuration. Handles save-or-suck, backup summoning, and any blasting that may become necessary. Cares about exactly three things: DCs, initiative, and spell penetration, in that order.
1 Focused Conjurer Malconvoker, bans Enchantment, Illusion, Evocation. Summons just have too much versatility to pass up. Focus mostly on summons.
1 Focused Abjurer War Weaver with some sort of persistence cheese, bans Evocation, Necromancy, Transmutation. Handles Abjuration, Enchantment, and Illusion buffs. After buffing, keep Teleport in the weave; instant escape as a move-equivalent (Su) is a big deal. Cares mostly about always being able to act; stats, feats, skills, etc. should be to that end.
1 Focused Transmuter War Weaver with some sort of persistence cheese, bans Enchantment, Illusion, Abjuration. Handles Transmutation, Evocation, and Necromancy buffs. Keep some non-Teleport escape spell in the weave; instant escape as a move-equivalent (Su) is a big deal, and teleportation can be blocked. Cares mostly about always being able to act; stats, feats, skills, etc. should be to that end.
Persistence cheese is preferably Incantatrix, but Anima Mage, Psycarnum Infusion/Midnight Metamagic, or whatever else you can come up with should be fine. Make sure someone takes Spontaneous Divination; I'm favoring the Malconvoker because that one seems most likely to have spare slots.
I usually like to work some free healing into a full party, even if only out-of-combat.