Go with the second product, the twin filter half mask. You can change out those filters very easily where the Neoprene thing looks cool, it also looks expensively disposable. Plus you are going to sweat into the mask and breath off a lot of water vapor.

I've only lit my jeans on fire when grinding titanium. Steel won't do it, so good stout pants and a cloth apron won't be so bad. Leather is good insurance for high speed items. I know a couple grinders who won't buff anything unless they are wearing a chain mail apron.

Hat, eye protection, and ear plugs. Ever get welding flux or some hot sparks from a grinder down inside an ear? Go ahead, just once, then you'll know why ear plugs are not just for hearing protection...LOL