Umm ink is another ball game, i know nothing about it. Seems from watching others its much harder to use. Out of the paints at foxy i would go Createx illustration maybe etac. You'll have a lot of support that way as many people here use them. You'll be surprised how far they go. Working on posterboard, about 1m by 1/2m, each time i use a color its generally a number of drops, usually totaling less than ten, and half of that ends up washed out of the brush in the end. The only time you'll fill a cup is doing a full background color. For your purpose I would maybe think about switching to a system of golden airbrush medium, and using the acrylics you normally use. You could kind of streamline your paint system that way. For now though i would get a commonly used set of paint until your real familiar with how it should perform. Then you can start playing around with a lot less frustration.