Given the conditions here, you really want to start out by perfecting your skills as a diver, long before considering lugging photo equipment. My first recommendation to you is that you learn to dive in a drysuit, and invest in your own dive gear before investing in underwater photo equipment. Those that do not own their gear tend to not stick with it in these cold waters: it's just too difficut to get a rental drysuit that fits. I dove my first 100 dives in a wetsuit, and I can attest hypothermia is not fun!
Once you can handle your bouyancy, currents, the cold and actually taking the time to look at what's down there (beginners tend to zoom by everything at first), than start with something compact, but versatile. Switching to a housing was a learning experience in itself in these waters: it took me a while to get used to the weight and size, and there are times I crave a nice small system, particularly when there's current.
That being said, the diving here is world class (particularly on Vancouver Island), and well worth the effort and $$ to explore.
If you PM me, I can recommend some excellent facilties for training.
Cheers,
Marli