Here is a collection of all the Sitefinity Stuff I have created.
Integrate Snipcart, a client-side shopping cart, into your Sitefinity site and start accepting international payments in minutes.
You can also use your existing Sitefinity eCommerce module products to drive the cart or migrate those products into the Snipcart Commerce module. A good option if you are looking to migrate away from Sitefinity's implementation.
There are widgets to display products, view orders as well as accept payments which is handly for accepting donations online.
You can buy the standard module which provides you with a Nuget package that deploys a Sitefinity Add-on to your project along with a class library. It also contains some sample Razor Views and Sitefinity eCommerce product migration script to help you with any customisations.
If you have particular needs to cater for then you can purchase the source code of the project and take it in your own direction.
New to Sitefinity or need help
I can also provide development services to help you integrate this module into your existing Sitefinity site or get a new site up and running.