I'm worried that I might be double dipping too much with these two exercises
The nice thing about the wood choppers and the Pallof press is that they both work the rotational aspect of the abs, which tends to be overlooked, particularly by beginners. And doing both of them means that you're getting concentric and eccentric loads from the wood choppers, as well as an isometric load from the Pallof press.
Don't worry about overdoing the abs. Unless you're training abs every single day, you should be piling on with a bunch of different exercises. So worry less about double dipping, and worry more about not quintuple dipping. You should be doing some exercises specifically targeting the rectus abdominis too, including top-down movements, as well as bottom-up movements.
By top-down, we're thinking of things like crunches. I like doing them on a physio ball, because it allows me to get up off the floor, and get more of a stretch before starting each rep.
By bottom-up, think toes-to-bar, or if those are too difficult, start with knee raises and work your way up.
it should build both these muscle groups so at least the 'bumps' are visible
You're going to hear this early and often, so here it is again; the visibility of your abs is dictated less by the size of your abs, and more by the amount of fat covering them. We live by the credo "abs are made visible in the kitchen". You should of course be strengthening them with exercise, but they will never show themselves until you get your eating habits in check.