Depending what you are wanting the Kids for, If you are wanting them for Meat/breeding for future meat I would go for a Pure Boer Buck. that way the kids will be 75% Boer . if you are hoping to milk kids once they are adults you will be better off going down the Dairy Route to make the Kids 75% Dairy.
There is quite a few BBGS members in Yorkshire so take a look on the members list of the BBGS website