Without looking at the cows and you describing them as club calf cows, I would say you should use a calving ease purebred Black Angus bull. I guess if it was me, I would be a little worried about large calves without the ability to calve them out on their own with clubby cows. The first priority has to be to get the highest percentage of live calves as possible. Personally, I have a commercial herd of Black Angus crossbred cows consisting of a lot of different breeds. The bull I have out on them is a 3/4 Shorthorn bull. He's pictured to the left. I will be using Angus, Shorthorn, and Maine Anjou genetics to get my final products.