.120 wall would be fine if you were doing a bag over axel set up.
Here are my bars:
They are 29'' length .25 wall 1.5'' OD. I still put a truss on them and the bag bracket I am using will spread the weight out on the bar even further.
I would make sure your bag bracket on the bar is centered first. You will want a crossmember between the frame rails where your bag bracket is or the frame will twist in. The front mount will definitely need more reinforcement both vertically and horizontally.
If you don't want to replace the bars you can switch to a bag over axel set up or mount your bags to the inner bars if you haven't bought them yet.