Google Drive is Google's file sync app that lets you store all of your files online alongside your Google Docs documents, and keep them synced with all of your devices.
Attach client scope files to draft quotes before approval.
Your quote approver can review the client's scope beside the draft quote, with the uploaded file attached from the scope form.
Send approved deal agreements for signature and record the link.
Your client gets the agreement to sign, and you get the request link and send confirmation on the project.