So in my quest to find somewhere that a) has the Taifun GT4 (non-TPD) in stock and b) ships to the UK, I've come across hisvape.eu. Based in Germany, seems to ship to the UK, has the GT4 in stock.
Doesn't look like red-vape.ch ship to UK either - it's not letting me choose a payment method. Like Smokerstore wasn't letting me choose a delivery method. It's a bit annoying that these shops don't just outright say they don't ship to UK.