What standard zoom f/2.8 for A99?

The Sony 28-75 f2.8 or it's sister lens the Tamron 28-75 f2.8 would be a good fit if you are not heavily into video. The Sony lens is a SAM unit , while the Tamron is screw drive ( and a lot cheaper). The Sigma 24-70 f2.8 is HSM drive, so would be okay for video, but I don't know if it is compatible with the A99.

I went for the Tamron and am pretty happy with it (not great wide open though).