All of the homes and apartments in the Presidio are managed and operated through The Presidio Trust (a Federal agency). The park features 1,147 housing units in 21 distinct neighborhoods. Nearly all homes have been rehabilitated. None of the homes or units are for sale; they are all rentals. You can inquire about leasing by visiting this link: http://www.presidio.gov/leasing/residentialleasing/
If you want to buy near the Presidio, there are several great neighborhoods that line it's boundaries: Cow Hollow, Presidio Heights, Laurel Heights, Inner Richmond/Lake Street. Perhaps you can look for a home that is close to the Presidio so you can take advantage of all it has to offer.
I hope this was helpful. If you have more questions please contact me.