Near-newby question: should I upgrade camera&housing or add a strobe?

[pooley]

Ask just about any decent u/w photographer and they'll go for the strobe option. Just think first if you plan on upgrading in the future to housing your 5Dii, as if you get a strobe that will only fire via fibre optic cord such as the s2000, it'll be useless with any 5Dii housing. You're better off with a strobe that can fire both fibre optically for now, then with a cord for the inevitable future upgrade. Sea and sea ys110 or inon z240 spring to mind

 

[Hotpuppy]

Puppy,
The OP already said the G9 was so-so. He knows the quality diff between a G9 and a 5D II and a ID Mark II, as do the other posters. He also implied he needed to be frugal.

Besides dissing everyone before you that has given him advise, you seem not to have gotten the point of his post. Of course, if he wants to get the best possible quality and doesn't care about $$, he should pop for the housing and domes and the rest of the $$$$ of gear needed to house his $5K camera. Seems to me that investing about $600 for a tray, arms and a decent strobe for his G9 is a good alternative.
Also, I will accept your critique of folks who use Point & Shoots when you show some of your U/W work and compare it to some of those who have posted here. As you said, money and great equipment does not automatically translate into better quality photographs. Your comparison of a G9 and a decent strobe like the Inon s2000 to a " semi-disposable camera with a flash cube" is nothing short of absurd.

Actually I think I go this post pretty well. He has a G9 and a 5d MkII. I told him he wouldn't be happy with his G9 if he is used to a 5d Mk ii. I know I wasn't. The G9 is slow, has high noise, and has a small lens. If you like that great, but generally people who own nice camera gear prefer what it can do. I know I lost shots because the g9 took too long to focus and did not do well in lower light. Your mileage may vary.

My latest G9 shots: Cozumel - Cinco De Mayo 2011 - UnderseaX - a set on Flickr

The bottom line is that if you are going to invest in a quality strobe *or* a case for a quality camera, I would say take a better camera. It really comes down to the diving you do. If you dive at night, in the dark, deep, in wrecks.... you need a strobe. If you want high quality pictures, like shallower diving, like to take pics of critters, and enjoy clear water during the day..... the strobe is less important.