I would say yes to get one but there are a couple other things I would bring up. First, you don't really need to have a skimmer until your tank has been cycled. Please read up on fishless cycling of the tank. If you already have fish then you will need to get testing equipment ASAP and get ready to do a lot of water changes.
Also, 10lbs of live rock is not enough IMO
. You should shoot for 1-1.5 lbs of rock per gallon of tank.
Lastly is the sump with bio balls. Be careful running bio balls as they can be a nitrate factory. You can still run a tank with them, but it does require maintenance so it would be best to figure that out right away.