Beginner in need of help

Hi every1 I recently took on a new hobby I have a 150 gallon fish tank and I am looking 2 set up a saltwater tank ... I have been told I need 2 purchase live rock and got a lot of different answers for how much ... How much is ideal for a 150 gallon tank and can I mix and match the different kinds of rock ... Also what wuld b an ideal protein skimmer and pump size ... The tank w the stand stands 6 ft tall .... And what other tools do I need 2 purchase for this ? Thanks for the help and I am very excited 4 the challenge ahead of me