Last month's rent and sale of apartment building

So, I am going to lease a studio directly from the owner of a house. He has informed me the house is up for sale and he thinks it will sell. One point and one question: Point - I checked and as long as the lease doesn't include a termination clause for the property being sold or conveyed, the new owner cannot evict me. They have to honor the lease and become my new landlord. Question - So I am going to sign this lease with the original owner. I paid him first month rent and will be meeting him soon to sign the lease and pay a last month or security deposit. My concern is, if he sells the house and I pay him last month, will the new owner be expecting last month too? Does he need to inform the new owner I already paid last month? Should I pay him and date it for my last month (1/1/13) so he can't cash it beforehand, and then if there's a discrepancy I can stop payment? Or should I just have the check as my receipt and make him and the new owner fight over it? How should I proceed? Thanks in advance.