For more information on the Alonzo Mourning situation try the Spurs Dominion Alonzo Mourning free-agent thread.
I would not have any problem bringing in Zo for a couple of years at the right price, and if he is deemed healthy enough to go. However, I understand the Spurs having reservations if they can go for a young talent like a Tyson Chandler, Keon Clark or Jerome Williams.