Hi iDiveChick. I use a Canon Rebel XT or 350D which is only 8MP. The new Rebel XTi has 10MP. I haven't posted any photos here but I do have a lot on another board you could take a look at. Rebels are relatively cheap, it's the housings and strobes that are expensive. The D200 is very nice but a lot more $$$.

As far as lenses, I've never seen flip down macro. I use a 10-22mm wide angle and a 100mm macro. I do have a Woody. Woody's diopter that is, it is a wet mount lens that I use shooting macro. Inexpensive and it works well. I'll post some photos here later.