Hoosiers or Dunlops, with most people running the Hoosiers. How long a set will last depends on how you drive, track, etc.. But in general, a set will last anywhere from 2 race weekends, to a whole season. I think I average about 3-4 race weekends per set. Daytona isn't tough on tires like some other tracks can be.
60A's are fairly new IIRC they are slightly harder compound than the R60's but not quite as hard as the next level up Dunlops. Somebody correct me if I'm wrong on this. The 60's are supposed to be the same as the RH2 Dunlops according to Adam from Hoosier. The R60's are just fine for Daytona.