my first salt water tank

[mytank90]

after reading threw alot of post on this site and others my wife when out and bough me a 90 gallon tank for fathers day .she and my daughter surprised me today when i was told to go pick it up /hehe .i was going to go get it drilled but found out its tempered glass and the lfs will not let her return it .after doing some more reading i saw overflows for sale .do these work ?i was looking at a eshoppe type one and a cpr one .like the cpr one .my tank will be live rock and the wife like corrals so want try easy ones at first .will i need a overflow with sump or can i just go liverock/protin skimmer and powerhead .thanks