there is enough material on the factory frame trackbar mount to cut it off flush with the frame, and then reweld in new location, but only enough for the reuse of the factory track bar. I have done this before.
When you cut the mount off, you lose some material, so a larger diameter joint will not fit. But the factory track bar will if you are careful in how much you cut off.
On my most recent project, I used the factory mount, in the factory location, with a currie johnny joint. Currie makes a "slim" fit joint for another (jeep jk) track bar application, with 1/2" or 5/8" through bolts. I used 5/8ths and drilled my mount out to fit.
I am running a heim joint on the axle side.
So far (500 miles) this has worked really well. I think two heim joints are too much and will rapidly deteriorate the joints, as well as increase vibrations while driving on the road. You need a little give in the joints.
The strength of a 1/2" grade 8, double shear bolt, is more than enough for anything youll throw at it, but I believe the mounts tend to rip off. If you can support it some more and beef it up, for you situation, id just cut the mount off and build around it with a lot more reinforcement. Move it forward and keep it on the same "height" or horizontal plane that its on now and build around it beefing it up with the rest of the frame above..