If you can find a Oly SP-320 or SP-350, you can get the AD mount and use all your stuff. The AD mount is relatively cheap. The SP's have full manual control and shoot RAW. They're about a year out of date, but you can probably still pick up a camera and housing somewhere. E-bay maybe? There was one on this forum a couple of days ago.
OLYMPUS SP-350 8.0 MP Digital Camera SP350 + Warranty - eBay (item 260205058007 end time Jan-26-08 19:05:42 PST)
NEW Olympus Pt-030 Underwater Case Housing for SP-350 - eBay (item 350018714859 end time Jan-27-08 17:12:15 PST)
OLYMPUS SP-350 8.0 MP Digital Camera SP350 + Warranty - eBay (item 260205058007 end time Jan-26-08 19:05:42 PST)
NEW Olympus Pt-030 Underwater Case Housing for SP-350 - eBay (item 350018714859 end time Jan-27-08 17:12:15 PST)