Experienced AOW certified divers can easily do the Hogan as a single, non-deco dive. The surface interval would have to be significant in order to have a second dive with a decent duration. I believe this is one of the reasons that a boat trip consisting of two deep dives at the Hogan is rather rare. But hey, the birthday boy gets to choose right?
The Hogan can be a really fun dive. My first dive there featured several wolf eels that are known to inhabit the wreck and a rather large mola mola (which was a huge surprise).
One of my friends saw a hammerhead shark during his safety stop there. You never know what you'll see at some of these sites. With the abundance of jellyfish in San Diego waters recently, I'd keep my eyes open for more mola mola (they eat jellyfish, right?).
Happy birthday in advance!