The Canon 60D is an excellent camera and should give you very good results in underwater photography. I recently was at a seminar on underwater photography. The opinion was that a DSLR with a smaller sensor was actually preferable to a full frame sensor for most users. The DX sensors (Nikon speak) accept a wider range of lens choices and the lenses are less expensive. You have your choice of the excellent Tokina 10-17 fisheye, or a good rectilinear lens like the Sigma 10-20, for wide angle. The other way to go is generally macro which usually means a 60 mm lens.
For housings, I noticed that both Ikelite and Nauticam make housings for the Canon 60D. Ikelite makes good serviceable housings. An Ikelite housing goes for about $1500 US. It is cheaper because it is a basic plastic box with the controls cobbled on. The plus is the price. The minuses are several. It is larger and clunkier than the metal housings. The controls are not always lined up just right or can get out of line. The housing is not quite a robust as an aluminum housing. Nauticam makes an aluminum housing for the Canon 60D which costs $3000. If you are price constrained, the Ike is the way to go. If you are not so constrained the Nauticam is much nicer to use. I have used a Canon G11 in an Ike housing for about 120 dives. It worked well but had limitations. I recently got a Nauticam housing for a DSLR and it is a marked improvement. That being said, I have a very high regard for the Ike housing and would recommend it.
Now I just did a fast survey. I bet that all of the major housing manufacturers have housing for the 60D. Canon and Nikon are the big boys on the block and the manufacturers tend to support their cameras. I bet the Sea and Sea, Aquatica, and Subal all make housing for the 60D. If you can, go to a retailer that specializes in underwater photography gear. We have about four of them in the US. It makes a difference to go and talk to them and handle the gear.
Now, do you need a DSLR housing? If you are diving just to take snapshots, I don't think so. If you know about F stop, ISO, shutter speed, histograms, RAW format or are more than willing to learn, a DSLR might be for you. If you just want to dive and take a few shots to commemorate your trip, a DSLR may be over kill. If you are the type who will sit at a blenny's lair waiting for that little critter to poke its head out just right for your photo, then it is what you want.
I hope this helps.
