wtb saltwater,live rock, coral

Hi Leng, My name is Joel and I am the current Des Moines Trustee and Vice President elect of GIRS.
My first advice is to slow down. You have quite a bit of time before you can put any life in that tank. First, Join GIRS so you can go to Seascapes on 22nd ave and tell them you are a member. They may have a 200 gallon box of Reef Crystals left from our last salt buy they can give you at a great price. Also, I wouldn't worry about live sand as many in Des Moines including myself can get you a culture from our tanks to get your "life" started. That will save you some $$.
Instead buy a couple of bags of Aragonite sand from Seascapes and put that in your tank with a heater and pump with freshly mixed saltwater. To do this right you will want the water to be from an RO/DI system. I don't know of a store that will sell this in Des Moines but maybe someone will chime in and get you some to get started. If you plan to do this hobby right, you need to invest in an RO/DI unit for yourself.
Then get an Ammonia, Nitrite and Nitrite test kit and start waiting for your nitrate cycle to complete. You can either throw some live rock or put some flake fish food in the tank to get this cycle started. There are many that would also give you some good "stuff" to start your cycle. Read about the nitrate cycle if you are not familiar with it. Get comfortable for awhile and wait because this will take awhile and this is never something you want to rush, about 6-8 weeks until the cycle is complete. At this time you can start thinking about getting some starter life. Fish from Seascapes and corals from me or someone else in the club.
Lastly read,read, read and ask questions. We are here to help.
Hope that helps, good luck and welcome to GIRS!