Well, this might be a bit more work, but how about if you add two options to the order form: will you be paying by credit card? and Are you in Europe?

Then, you could have 3 emails, each with only a *single* payment option. Make the decision for people since they're having trouble with it.

The only problem I can see is if somebody says "no", they don't want to pay with credit card, and then change their mind. What will happen is they will attempt, fail, and then contact you for a new paypal address. I can see that being a potential hassle, but how often would it really happen?

Jim