http://www.fatcatmotorsports.com/FCMstops.htm#M10

If you order them make sure you order them with the dust boots, as the dust boot is built into the standard MX5 bumpstops, and will come out when you swap them.
They are quite cheap to get to Australia, about $120ish aus dollars all up with dust boots. Cheaper then buying new bumpstops from mazda...
Hope this was some help..
Ryan