I'm guessing he has no experience with underwater photography at this point. If I'm correct, forget the housing for the 60D for now.
The s110 has a few options available; he can go for the OEM Canon housing which is fine and will go to 130ft (maximum), and is the cheapest of the lot. If he wants better, he has to spend more and go for either the Ikelite (rated for 200ft) or the Recsea (most expensive, 262ft rating).
I have the Ikelite housing myself for my s95, and it works great. One small issue I have is with the shutter "lever". Because it isn't a button, it is difficult to gauge the "half press" for AF vs the "full press" for taking a photo. Otherwise it performs well.
The gopro doesn't need a 3rd party housing. The housing it came with originally is sufficient.
Lighting is essential for underwater photography. You must have strobes (at least 1, 2 is better). I use a Sea & Sea YS-01 for my rig, I haven't got the budget to add a second light yet.
I suggest he go to http://www.bluewaterphotostore.com/ and browse the choices. He can also email them to ask for kit suggestions (he will need a tray, and handles, and arms for the light etc...).
Why do I say forget the 60D for now? Because housings for DSLRs are crazily expensive, they are huge and bulky (learn to dive with a P&S first), you have to buy more expensive ports for different lenses, and if it leaks, you are going to be one sad panda (moreso than with a P&S).