Just wanted to post the update/resolution - I ordered PyrocatHD from Formulary this morning, and they shipped it today to Europe destination for me - they insisted that to ship dry (Pyrocat) kits by airmail is no problem (they used USPS Global Priority Mail), and I should have it there next week. So I understand that I could've packed my two 10-liter sealed dry kits of Pyrocat and basically do the same.

Either way, I'll have the developer hopefully at the location next week - so all turned out well.