I humbly put forth a tried-and-true favorite: AD&D (yep, Second Edition) Complete Book of Necromancers. Admittedly, it's a completely different system; however, it has three kits that you both may want to look at. If nothing else, it'll give you some intriguing new ideas (and part of it, at least, can be converted in some form to 3.5):
Anatomist: The Anatomist kit is intriguing, mostly for being what amounts to the Dr. Victor von Frankenstein of necromancers. They use necromancy as a means of healing in conjunction with the Anatomy and Healing non-weapon proficiencies -- useful if you find yourself lacking a cleric, at least to a certain degree. The main drawback is that the Anatomist is definitely not someone you want anywhere remotely near the front lines, particularly given the kit's lack of weapons for proficiency, and that you can lose the kit's benefits if you don't autopsy at least one corpse every month.
Deathslayer: If you want to fight fire with fire, the Deathslayer kit is for you. The Deathslayer uses necromancy to strike at the undead, using their own Negative Energy against them. Best when coupled with some moderate melee capability -- Talib, the NPC Deathslayer in the book, was a 5th level human fighter before he dual-classed into the Deathslayer kit as a means of destroying any lich he came across (after a lich had killed what little was left of his family).
Philosopher: The Philosopher sees necromancy as the Art -- best for neutral-aligned characters (lawful neutral might actually be best alignment-wise, depending on personality). For them, necromancy is a tool (much like one of the previous posters had commented about Vodoun's view of necromantic practices). Philosophers tend to also be very educated and book-smart.
As far as converting the kits over... the Anatomist is likely the most difficult one, particularly now that they've changed healing spells from being Necromancy sphere in AD&D to Conjuration (healing) in 3E / 3.5. The Deathslayer... I'd say Fighter / Wizard (Necromancer) / Eldritch Knight as the most likely bet; Hexblade / Dread Necromancer would be interesting thematically for showing how the obsession with fighting undead carries with it a terrible price, as the use of Necromancy affects the character (through the Dread Necromancer's gradual transformation into a lich). For the Philosopher... straight-class Archivist is far and away the most likely choice for following such a concept.