Back about 15-20 years ago, I used to source my Amidon products from RJ & US Imports but they closed down a while ago.
You should also search for the FAIR-RITE range as they make what is essentially an Amidon equivalent, and some are available through Element 14.
https://au.element14.com/fair-rite/59430...dp/1781257
Depending on final use, contemplate the "61" grade products as well, eg Amidon FT240-61 or equiv.
Doug VK4ADC