Need some help with buying stuff.

So I'll cut this short and neat as to avoid any long drawn out explanations. I'm from the UK and I'm trying to buy the Sonic Collaboration edition of the game so I can get those much needed inventory boosters and other goodies. Problem is that as a UK resident I can't access the store to buy anything because PSO2 hasn't been released to Europe yet. Tried to work around using PayPal on the official Xbox website and that didn't work and I've been told the best bet is to buy a NA gift card and use that to buy anything but I have no idea what I'm doing.

Can someone from the UK who's done this already please give me a hand? Step by step instructions would be a blessing. Thank you.

Can you still Purchase the Founders on NA? If it is still possible, you can also Get someone to Gift it to you.