what exactly do you host?
because i really dont think you know what 12 TB of bandwidth means..
many a times, we receive enquiries from potential customers saying:
can we use about 450 TB of bandwidth per month on your unmetered package?..
if you do know what you are talking,
then i'd suggest you to go in for a dedicated server...
with your kind of storage and bandwidth needs...it would cost you no less than $1,000 per month(you'd need a 50mbit dedicated line)