Okay never mind the ideas i had before.
The better the contact between the block and the water the better. I might need a heavier stronger pump but it might be worthed. Let me sketch real quick what my idea is, I'll model it in 3d tomorrow. Anyway I was wondering if this would work...
All the thin copper piping/tubing whatever you call it, is soldered together and onto the copper plate on the bottom, so it works like a big heatsink with canals that are all thermally connected and water being forced through. It might kill my pump so I'll need a big one, but do you think this idea might cool 'Well'?
Instead of drilling all these holes to make a 'cavity' or space in the block, I'll try to solder different copper plates together on the sides, which would be waterproof, and then put 5 to 10 mm acrylic plating on the top, depending what I need and can find.