unmarried partners visa

My boyfriend is a british citizen living here on a work permit in the states. We are looking to apply for an unmarried partners visa .
We have lived together 14 months and plan on applying once we fulfill the 24 month requirement.
As far as proof... we have the lease statement which has both of our names. After doing some research though, I found that at least 10 different letters sent from bank, utilities and the sort with your name/address on it must be provided.
How do you get these? F
One 90% of my bills are paperless and two my boyfriend had utilities in his name.
What else do you need?
thanks!!