Which Canon lenses to use

Since 1 week I own a Sea & Sea housing for a Canon D60 camera, yes I know it is a old camera but for me this is the first steps in the digital SLR underwater photography and it was a good deal.The housing is equiped with the standard flat port, a extension ring and a dome port. What are the best lenses I can buy for this set-up, and I mean not the most expensief. I like to have a macro lens but should I go for the Canon 60mm or the 100mm. For the domeport I'm open for any sugestions..

The 60 mm and 100mm both do 1:1, the difference is the working distance and the perspective. If you're in the Netherlands and dive regularely somewhere here (Zeeland etc), i would suggest the 60mm, but this is a EF-S lens that only works with Eos digital cameras from the 350 and the 20d onwards (at least without tricks like extensions). At least look into that before you buy. The 50mm is not nearly as nice, it doesnt do 1:1 without an extra thing, and it changes in length during focussing. The disadvantage of the 100mm in murky Oosterschelde water is that you have to keep so much distance to the subject, that the water will make the image not too sharp.

The 60 mm and 100mm both do 1:1, the difference is the working distance and the perspective. If you're in the Netherlands and dive regularely somewhere here (Zeeland etc), i would suggest the 60mm, but this is a EF-S lens that only works with Eos digital cameras from the 350 and the 20d onwards (at least without tricks like extensions). At least look into that before you buy. The 50mm is not nearly as nice, it doesnt do 1:1 without an extra thing, and it changes in length during focussing. The disadvantage of the 100mm in murky Oosterschelde water is that you have to keep so much distance to the subject, that the water will make the image not too sharp.

Why can't I use this 60mm Macro EF-S, is this a different system? And what about wide angle?

google and wikipedia are your friends..... http://en.wikipedia.org/wiki/Canon_EF-S_lens_mount ; the EFS lenses sit more inside the body so the lens mount has to be able to cope with them.

Wide angle of choice nowaydays seems to be the 10-17mm tokina fisheye, but again, check if this fits. An alternative is a fixed 15mm fisheye (I use that for my canon 20d, because the tokina wasnt there yet)