Rough watercolor paper may be a bit *too* rough. Some papers have a heavily textured side and a slightly smoother side. If it looks like the WC paper you already have has a smoother side, try that first.
And see if you can find some other papers to try. Everyone has their favorite, and what works great for me may not be the best choice for you. Since you like to use ink in your work, you may want to try Bristol smooth-- it won't take as many layers of cp as a rougher paper, but the pens will *love* it.