...
Forms are quite decent looking and you can style them to match your site and / or embed them in your site.
See also https://docs.google.com/document/d/1LotFpatJFbQBw5KLvD7Sdy5ixfsVc5GkZP267xvwmRQWebsites and Salesforce for more info and use cases.
Setup
http://www.aakonsultaakonsultpayments.com/docs/AAkonsultPaymentsInstallationManual.pdfinstallation-manual/
Documentation
http://www.aakonsultaakonsultpayments.com/docs/AAkonsultPaymentsUserManual.pdf
Notes
Questions