Do you know of a sales or marketing service or software that creates a sales funnel?

You can use any of the Sales CRM applications. You have cloud based CRM applications like Salesforce and also you can set up your own customized CRM solution with any of the open source CRM platforms like Sage or Vtiger.

Using a CRM you can manage the complete sales cycle of your customer engagement right from the stage of Prospecting to closure and delivery and also you can set reminders as needed to give you alerts on activities due