Variable Payments for Subscription Newsletters

Dear everybody,

I want to offer a range of payed subscription newsletters (ten different but related topics). My planned pricing scheme looks like this:

For 5,5 € per month you get the main newsletter + 2 topical ones of your choosing
Any additional topic costs 1 € per month

What I am looking for is a payment and administration solution. The user should be able to quickly choose his favorite combination of newsletters and confirm the monthly payment. Afterwards he should be able to come back at any point and change his subscriptions (with his monthly payment changing accordingly).

The target group is largely German, so a solution allowing for bank transfers would be ideal.

Thanks for your help,

Peter

[No bumping, thank you.]