Congrats!
Dont forget to check with your homeowners insurance to make sure that the long arm is covered. I would also draw up an agreement with your partner in regards to the arrangements, cost to purchase, etc. IF, heaven forbid, anything happens to either of you, the family has a document describing your partnership in this purchase and arrangement. Just to keep it "legal". I assume the price was not inexpensive even with the sweet deal.
Have fun!!
sandy