Non-good Human / BG: Wizard's Apprenctice

5 Wizard > Necromancy Specialization (Spell pen -> Greater Spell pen)
+2 PM (Extend Spell, Enervation)
+2 RW (Weapon Focus: Ranged Touch Attack)
+6 PM (Practiced Spellcaster, wizard -> Combat Casting)
+4 RW (8th Level spells... Improved Crits: Ranged Touch, Empower Spell)
1 Rogue (Weapon Finesse)

Note: At level 20, it can only cast level 8 spells because of 1/2 PM spell progression.