Tank looks great. You did a nice job cleaning it. I don't see any scratches and that is great because these are known for being scratched easily. Did you add salt already and how is the water parameters. You might have a little die off from using the old sand but it will filter out. You should get about one pound of live rock per gallon of water. Most pet stores will carry this if they sell salt water supplies. You can order it online but it will not be cured unless it is shipped in water. You should get some live rock before you add fish.
The other option you have is getting less rock and have bio balls in the back filter area. This method is not a efficient but it will work. It tends to lead to higher nitrates which coral cannot live in.
It looks as though you are off to a great start. If you have any questions I will try to help. I worked in a pet store for 3 years in the fish department. I specialize in the saltwater aquariums and have a passion for the proper care of the aquatic creatures.