Attaching a quote to a Lead

Attaching a quote to a Lead

I am going through the trial. Is it possible to attach a quote to lead? The reason I want to do this is so I can separate existing customers from prospective customers. If everyone is entered as a contact or account I do not know how to distinguish between users and prospects.  

I know you can attach quotes to potentials but that seems to be very limited in what information you can attach to a potential. I prefer the leads category much more. 

Any help is greatly appreciated.