Invoice system needed inside WP

Hi, does anyone here uses a working invoice system within WP? I did some research but most plugins (paid/free) are using PayPal or some payment gateway not working in The Netherlands. Our most favorite payment system overhere is called iDeal (my client likes to use it).

It's not the payment part what interrests me most, but the invoice creation (to PDF). This system needs to have a utility to export invoices to a format that MS Excel can import.

Maybe there is a solution using several plugins?
Thanks for responding.
Milan.