Lead Conversion???

Hello,

I Have an Enterprise edition of zoho. We know that a Lead can be converted to an account, contact or a Potential. My question is can a lead be converted to an Sales order or a quote . If a lead cannot be converted to a salesorder wat else can be converted to salesorder.

My aim is simple when a lead appears in zoho till the last stage i should be able to see from which lead source it came. So i want the lead source auto populated across every where i.e salesorder, quotes,invoices etc...
How can this be achieved.