Need 4-post lift capacity recommendation

I have a 9000 lb capacity 4 post lift also. Make sure you get one that is wide enough to hold your dually. Look at the distance between the posts. I have to fold my mirrors in to get on it. Plus it's best for me to have someone to help line you up on the lift as my pickup wheels are right on the outside edges of the runners. Go bigger if you can and make sure your dually has room. My puller is a 2009 Chevy 2500 HD with a Duramax.