I haven't seen RAM blocks, because RAM cooling isn't as standardized. Otherwise be of good cheer; what you want exists.
People used to buy water cooling one piece at a time - pump, reservoir, tubing, cooling heads. What you are seeing is kits. These are built with the minimum number of pieces to cool something, so they cool the CPU. You can usually get more pipe and cool a GPU or, if you can find waterblocks, your chipset, RAM, or coffee. But these would be add-on pieces to a kit.
The topology for this isn't standard, either. Split the pump output with a Y to two waterblocks? Have two separate outputs? Put the GPU waterblock downstream of the CPU waterblock?
I saw an article or ad with several alternative diagrams recently. If I can find it again, I'll post the link so you will have much more concrete information. But right now this is sort of a do-it-yourself on top of the base kit.