Well I'm glad you like the pics.
Both photos were taken at about 10m (30feet) IIRC. The equipment was a housed D70 with a 60mm micro for the seahorse and 12-24 for the coral. The housing is a Nexus aluminium housing.
Bill, as for what you should use then it really depends on how serious you want to get. Housing a Canon SLR you will be quickly running into the thousands of $$. If it's to snapshot what you see you maybe better off buy a digicam + housing and sticking a dedicated Underwater Filter in to rebalance the colours (water soaks up colours very quickly - starting with the reds). You can get some great photos with even this simple set-up see
http://www.magic-filters.com/gal.html
And yes, you can even buy a complete canon digicam +housing set-up if you wanted.