Check out the 3M or Sundstrom websites. We use the Sundstrom reusable respirators on the farm for spraying herbicides and pesticides but I'm sure they'd have one to suit your needs as well.
3M:
http://www.3m.com.au/3M/en_AU/company-au
Sundstrom:
http://www.sea.com.au/sund/menu_prod_sund.html