I only use b&r bar. I actually carry it in the front door of my gym with me. Sucks getting it in and out of the car, especially in the rain since I have to cover the sleeves with plastic bags.
I was under the impression the extra half inch was there because that's where most people should have their shins. I figure a custom knurling on a bar designed by you will be a better guideline for stance width than I can do myself by eye.