Wizard 3/master specialist 10/archmage 5/something cool 2// Dread Necro 8/Walker in the waste 9/Something cool 3.
On the wizard side, I actually recommend anything but necromancer, for optimization reasons. For obvious flavor reasons, take necromancy.
You get full wizard, and 19 dread necro, but can make mummies. If you decide to become a lich, take the 10th level. If not oh well. If you don't become undead ever, take tomb tainted soul for free unlimited healing. If you do give in and become undead, take it and retrain it out when you do.
On the wizard side, something that lets you cast in light armor is not a bad investment. Take it for some of those "Something cool" levels.
Good race- Human, or something with an int bonus.
Stats- Int>Cha>Con=Dex>Wis>Str unless you plan to be in melee with those skeletons. Then Int>Cha>str=dex=con>wis = Way to mad to bother.