I'd choose flow formula acrylics for illustrative work, similar to that seen on these cards.
Making a Stay-Wet Acrylic Painting Palette
I made my own wet palette with a shallow tight lidded container,
1/ a rack goes in the box first
2/ a sponge goes on top of the rack
3/strength paper towel wraps goes around the rack and sponge and the sponge and base of box is dampened so that the top paper towel stays damp but not flooded in water. The paint applied to this paper will stay damp while working. Place the lid on the box will keep the paint usable for days.
Storing Your Travel Kit of Acrylic Paints.