Steelheadman,
Regarding the steamer clams. I usuallyl let them spit in saltwater. I know the cornmeal is suppose to make them spit, but I am not sure about sitting them in fresh water. I suspect they will be fine though.

If cooking say 80 clams, I usually pour in 2 cheap beers, add some garlic and then put them on the stove until they steam and most of them are opened up. Water will work just fine also. You don't need a lot or it will boil over quickly.