Lease Addendums for this situation?

[Brenda Chen]

Hi, I'm a first time REI who just recently bought a multi family in Boston, MA.

I listed a vacant 2 bed, 1 bath unit for $2,450 ($1,225 per room). I have one strong candidate who is really interested and wants to move in ASAP. Initially he was interested in one room, however the second bedroom has not been filled yet. It’s been difficult finding another qualified candidate these two weeks. He moved for a new job and is currently on extended stay, so he wants to secure the place immediately.

Fortunately for me, he's willing to pay the price for the entire apartment while we search for a roommate. First, last, half deposit. His take home income is more than 2x rent (apartment). 

Any thoughts or concerns about this arrangement? Is this a sublease situation? What addendums should I include in the lease? All guidance is really appreciated, thank you!