I will just tell you what I use, you can decide if you like my setup or not? I have used this arrow & broadhead combonation for six years & 4-elk.
Easton XX-78 Super Slam 2219's Topped with 125-grain 3-blade Muzzy Broadheads.

My thinking maybe WAY off? I like heavy arrows & heavy broadheads for elk hunting.
I think you have plenty of KE in your current setup to take any bull.

good luck,

wk