osCommerce - which merchant service/payment gateway?

I'm in the midst of a project for which I am using the osCommerce shopping cart and I'm currently trying to find a merchant service and payment gateway that will integrate smoothly with it. I'm currently leaning towards payQuake (http://www.payquake.com) as their fee structure is quite reasonable, but I'd like to know what others have used. I'm sorry for going slightly off-topic, but I'm sure many of you have experience with this issue. Every shopping cart *does* use a database, after all, and I'm sure someone else will find this useful, too. Thanks a lot. Edward Dudlik Becoming Digital www.becomingdigital.com