Re: Respirator?
I don't know how much the filter media cost for those models, but my respirator for organic vapors (i.e., the one I used when laminating) has very expensive canister filters -- maybe 50 buck for a pair. Those canisters also would filter fine particulates, but I didn't want to clog up the expensive canisters with dust, so I bought a less expensive mask that has only the P100 particulate filters. This second mask was much cheaper and the filter media was inexpensive, too, which encouraged me to change it regularly. Perhaps the models that Wood listed can take the particulate-only filters as well as the organic filters.
I saved the respirator with the organic filters for working with resin. If I had used that respirator for grinding, I would have been buying lots of expensive cartridges!
A full-face mask would have been very nice for grinding, though. I don't think I'd want that for 'glassing, though.