I don't know a lot about knife techniques, but the Kabar TDI intuitively seems like it would be easier to learn. Good price and shape is a bit more adaptable to concealment.
What's to know, you just grab it and start cutting! Unfortunately, this is the thinking for many people when they talk about blades for self defense. Is not just a grab, open, cut situation. Knives are in a whole different category (mentally) where self defense is concerned IF you TRULY consider what it means to actually use a knife in defense of yourself or someone else.