I'm a software developer at 2Checkout.com. If your looking for a 2Checkout plugin, take a look through my Github profile. 2Checkout's integrations team has taken over support for the 2Checkout plugins, but please don't hesitate to contact me if you have any issues.
Thanks to the hard work and dedication of the open source community, I have had the opportunity to contribute to dozens of ecommerce platforms. If your working with an open source cart application and could use some help, feel free to ping me. There is a good chance that have worked through similar problems and may be able to help you out.