The North(TM) 7600 Welding Respirator looks like it would defiantly get the job done.
I like the 3M 2097 with a half mask.
It fits under my hoods, filters easy to replace, available in local stores, and seems to do the job.
If cutting with plasma, welding any plated or painted (even with the paint ground off) metal, I always wear this respirator.
I'm not sure that even the dust from grinding is about as harmful, maybe more so, that welding fumes.
I try to remember to wear if doing much grinding. Flapped disk put out a fine dust that can not be good to breath.
Floyd