If you could swing it, I would definitely recommend the elite set over the pro set. If you get the elite set you get the digital strobe instead of the yellow one. The digital one gives you control of the flash output which helps you not to 'burn' as many subjects. The wide angle lens is compatable with the dc500 but the 3x,8x, and 16x lenses are not. I tried it since I had purchased them with the predecessor the dc310 but got a weird flash back ring in many of my pictures. In terms of the battery, I can consistently get about 1 hr 45 min on a charge. They say that it is important to completely charge and completely drain your battery the first time you use it.
I bought my elite set from leisure pro and didn't have the greatest experience. I got a unit with the old firmware and the extra battery charger did not fit the spare battery. I had to argue with them for about 10 minutes until they finally just told me to call SeaLife directly. The customer service dept at SeaLife was great. They sent me one of the new chargers and explained that the supplier had distributed the wrong ones and that a recall had been sent out (but I guess my salesman at LP didn't get that info) Anyway, just make sure that your firmware is upgraded to the PIE5 version. You can find that info on the Sealife website.
Just FYI, if you do ever flood, save your disk. Between the 5 members of our dive group, we have managed to flood several cameras. As soon as possible rinse off and dry your sd or xd card and you should be able to access your pictures. We flooded a 5060 with a compact flash and the card was extremely finnicky but we finally got the photos to copy. I bought new cards to use in my cameras but at least the pictures were not lost.
Good luck and enjoy your dc500!!
