Debt is slavery and so on. Let's not get too hung up on the fact that I dislike it.
> Most e-commerce sites I've used in the past year offer Klarna or some similar service and all of them have been implemented as just another option in a set of radio buttons.
Radio buttons is fine. It's the defaults and "are you sure you don't want to pay with credit?" questions I'm bugged out about. I don't have an issue with them offering it as an option. I've seen it with multiple websites using Klarna for payment handling.