Loads of good points. Don't be afraid to start off small.
I'll be the first person to put my hands up and say I aimed too high and thought I could handle it.
I bought myself a Fuji S7000 semi-pro and had a housing built, but I hated it.
Although it took good underwater pictures, it was cumbersome and unwieldy. I got to the point where I wouldn't take it in as it was too much to handle, which meant it was essentially useless.
Nonetheless I got disenchanted and sold it. I put the money away for a few months and redefined my horizons.
With the proceeds I bought myself a Canon S70 with the matching housing. Being soooo much smaller I can clip this onto a D-Ring, and if I need to let it go it just floats into my body without getting in the way.
I feel like I needed to learn to take photos with it again, and I did. It takes time but small steps help me learn.
And now I have two underwater rigs which work just as well above water. I have this S70 still, as it's got a great 28mm lens on it, but I also have an Olympus E-300 DSLR and Oly housing too - and I use that when I want to take 'arty' shots or 'Macro' stuff, as it has a proper macro lens, but usually when I dive with that I dive with a patient buddy, or solo, as it's more complex and people get bored with me faffing. Both cameras have underwater modes which helps, and they take great images.
I still use the S70 most of the time though. Best thing for me, though, is that both cameras do RAW, and both use CF cards, which means I have a stock of 4Gb cards which'll work in both cameras
