"Wait, that didn't work right" - the Dysfunctional Rules Collection

[willpell]

Just Spec, but it will stack with regular Weapon Specialisation if you were willing to eat 4 levels of Fighter to get it, as you say. If you want to Dual Wield, take Oversized TWF from Complete Adventurer, though we're not exactly talking high-op here. 2nd level Cleric spells and +4 damage per hit at 8th level isn't exactly gravy.

It sounds comparable to Paladin, which is about as "optimized" as I like to get.