Yeah, for a while I kept thinking I'd be able to maybe find a real shallow SS bowl. As I recall, the diameter may be around 12-14 inches.
But I gave up after I got the wok. That's why I was asking if you could fab one
On a side note, my burner is in good shape, but I wanted a replacement so as to not wear out the original. When searching for parts for my Weber 101001 Gas Kettle Grill, I ran across a replacement burner, but it's not truly a replacement as the flange is upside-down, so it won't work with the baffle. I think it's just patio heater burner.
I got it anyway because it was cheap. It drops right in and works great as a wok burner. They've more than doubled in price since then.