You can build the entire SharePoint site application using Quest Web Parts, SharePoint List/Document Libraries, Master pages, Web Part Pages and other elements and save the site as a template with content included. Make sure that you have minimal features enabled in the original site before you save it as template so that when you upload this template and create a new site based on this template, you encounter less problem associated with feature dependencies. Quest Web Parts took this approach to provide the ready-to-go site template for Help Desk application, Project Management application and etc.
You can also export the configured individual Quest Web Parts and save it on the file system. The configuration you have done to this web part will be saved as well. You can import the saved web part onto a different web part page, different SharePoint site. You can also upload this web part into the site's Web Part gallery and allow Site Designer to reuse this configured Web Part whenever they want to add a new Web Part to the page through the "add a web part" link and dialog.
If your SharePoint staging envrionment is similar to your production system, this entire site template approach will work. The second approach will also work as long as you have the List/Document Library that you used in the configured Web Parts are also available with the same location and name in production system.