DO NOT EVER use play sand in a salt aquarium. It's filled with silicates that cause all kinds of algae issues when stirred up. Live sand from a bag is also a crock. By the time we get it any live bacteria is dead, but the damage has been done. It's not too much more considering the smaller size of your tank (I'm setting up a 240 gallon, which would cost a small fortune for the live stuff, lol).
And for salt go with the best bang for buck, which will be IO (instant ocean).
And good call waiting on the pipefish. There are plenty of awesome fish for your size tank. Chech out liveaquaria.com and they have a really good description and sizing guidelines too.