The Send Email with Attachment can take a map of documents to send as attachments. Just make sure the map contains all files you want to attach.
You can get the workspace attachments from the User step>Attachments and Notes>Output Attachments and the Workspace form would be in the variable you specified under User step>Form Data Mappings.
If you use and XDP for your Workspace form, you'll need to use renderPDFForm to convert it over to PDF.
Jasmin