Ultimate heatercore
http://www.heatercore4u.com/2-210.htm no questions asked.
The reason heatercores are better then a black ice is because the black ices are alot smaller. if you had willie build you a custom Rad to the same size as a heatercore it would outperform it but not by much. Heatercores are the way to go if you dont care about room you take up with them. otherwise if your extremly tight on space just get a BI. or talk to willie for a Custom Rad (which by the way aernt cheap)