For occasional tow paths? Brave. I've had a couple explosive sidewall failures on GP4000s - I don't know that I'd trust them on gravely tow paths. I'd probably go something with proper bead to bead puncture protection like a GP 4 seasons or the above mentioned Michelin Endurance
Don't know about shipping to you but the 25mm GP4 SII is on sale here:
https://www.universalcycles.com/shopping/product_details.php?id=64447