Monk 1 with Kung Fu Genius or Carmendine Monk will give you Int to AC. There are enough ACFs that one of them probably works well with Swashbuckler, although IDK off hand.
Factotum 3 will give you Int to lots of things, but only a limited number of times / encounter. Works a lot better if you take the Font of Inspiration feat as many times as possible. Also gives you extra actions, but not until Factotum 8.