I actually have a D300. I saw a D300 Subal housing for a great price on eBay.
I love my Canon s1xx series, and have a recsea housing. I primarily shoot macro, but i have a D300 for wildlife photography above water.
I thought hard about getting the D300 housing, but I take video of animal behaviour underwater at times, and wouldn't want to lose that.
So I thought, next best thing, look for a D300s housing. And yes, I would need the body.
@Crowey, feel free to PM me.