The cross drill is an easy one and it performs quiet well. I have made one for myslef but instead of the 4cross drills I have three 10mm wide drills vertically and four 6mm wide drills horizontally on a 60X50X16mm copper block with 3/8" jackets for water in /out.
It lowered my temperature 10*C from the previous air cooled system.
wish you good luck!