I like the carib sea sand myself, either the cichlid sand or the aragamax sugar sized(if you get the sugar sized, get a pre-filter for your intake)
I like the escargot shells from amazon.com for shellies. Some people use turbo snail shells, but I find they are too heavy for the fish to move around and position them the way they like, which is half the fun.
You can also get some medium sized whelk shells for the altolamps, and stand them up, half buried, so there's a vertical opening
Wait...did you just dump the fish in after you filled the tank with gravel? I know aragonite can be a pain with the cloudiness, but I hope you let it settle before putting in fish! Yikes! If it isn't the cloudiness that will hurt, it will be more of the other components of water chemistry that would be harmful!