If you mean on the MLS, that's up to the rules on your local MLS. But the answer's probably "no." You can do a "sale" and a "rental"--and have two listings that way, but not two "sales."
Suggestion: If you're willing to continue renting, list one under "sale" with the comment that seller will be willing to consider owner-financing or a lease-option. But another under "rentals" with a similar notation--that the owner would be willing to consider a lease-option or lease-purchase. Check with your agent to see whether such an approach would be permitted.
Hope that helps.