Potential Revenue Field

Potential Revenue Field

Okay... what is the best way, within the Potential Form to capture these two different scenerios, and keep the functionality of tracking Revenue accurate.  
 
Our Sales Rep would work on a HUGE deal with a major Retailer for 2.5 million bottles of our product for 1 year. How would I capture that in a potential? (2.5 million x price/unit)/12 (months in a year)?
 
Sometimes our sales people cut deals for ONE year, others cut deals for one time shipments. The one time shipment is pretty simple... It is when someone is working on a deal moving forward... Do you just estimate Annual Sales and divide by 12 months, then use that figure in Revenue?
 
Should I create a new field that Annual Revenue, and tell them the rule the Potential Revenue is MONTHLY... I guess that is my question. Should that field always be a MONTHLY number!
 
Thanks so much for your ideas on this...
 
Earl Stoddard...