I would really appreciate suggestions as to which are the best respirators,why you think so, and where you purchased it. I don't mind 'splurging' with this purchase...too important.

For those who might find it of interest, the following is a useful government website regarding choosing the right respirator for your individualized needs.
Many thanks...Bob

http://www.osha-slc.gov/SLTC/respiratory_advisor/advisor_genius_nrdl/advisor_genius.html