The paulownia I used on my Redfish King is from the source Earvin listed:http://www.paulownia-timber-sales.com.au/
Timber from that place isn't very high quality - not really 'furniture grade' - but is quite suitable for strip-built kayaks.
If you're looking for higher quality timber, TomN mentioned to me at a training event that he knows an excellent supplier named 'Tony Ferris' ... A quick Google search says that he is located in Coffs Harbour, company name FESA PTY LTD, phone number 0427 543 922. Can't find a website for him.
I'll use the remaining timber from Paulownia Timber Sales on my next project, but might try Tom's supplier when I order new stock.