Looks like that cow doesn't need much help in the phenotype or fleshing department. She is a real good looking girl! I would go with a real maternal bull here, and breed to get females. Genex has 75% and 90% male and female sexed semen, and I know other companies who only have 90. I would breed her to a good maternal bull, with female 90% sexed.
I would also, not necessarily recommend Mulberry, because of the "brian bandwagon", but I would suggest an Indeed bred bull, or Indeed if you can get semen on him. I was just at Six Miles yesterday actually looking at the new calf we (Genex) has leased from them. He is an Indeed son named Win-Chester. He is actually their sons bull. Anyhow, he would be GREAT for your cow, as he is long, with great muscle expression, a long, thick, square hip, and plenty of grow. I would say he is at a 6 frame. He is on their flyer's for their sale in April, and you can see that on their website. I would imagine you wont be able to get semen until early May, as he has to go through their sale, and then down to Billings to collect. We also saw his dam, a Norseman King dtr, a $20,000 female. She too, is long, square made, with great rib shape and adequate depth.
I have posted some images of Win-chester, taken yesterday (Feb 11th) at Six Mile.
Also, just for fun, the reigning World Champion Angus female in her "natural environment". She is due soon, and bred to Sakic.