If you are wanting to mount a rifle and walk away without concern of the unit falling over you need one of two things. Exceptional quality or weight.
I have a Gitzo Carbon mountaineer tripod with arca Swiss head that would do it, but you're looking at about a grand. It's not so much what the system weighs, as long as it will hold the weight. In that, my gitzo has a hook at the bottom that will hold sand bags and the arca ball is rated for about 15ish pounds. The whole setup is about 6 pounds as I remember.
Heavy systems will work well also and are much less money. It just depends on how mobile you are looking to be, or if you have a pack mule.
If you are not looking to mount a rifle and walk away you could get away with the medium size manfrotto ball heads that have a friction control lever. They are very reasonable.