Hi if you really want to set up a reef tank and do it right, id suggest some reading first. I wouldnt worry abotu buying anything else until you get the book "the conscientious marine aquarist" by robert fenner. this book is amazing and will help greatly, the book should give you a good idea on what filters etc do what, lighting, substrates, decor, fish compatability, etc etc. Also i would suggest doing lots of reading on this forum and asking lots of questions, we will all try to help you as much as possible, and guide you in the right direction, but i would defitnitley suggest getting that book and reading it, it was a huge help to a lot of us on this site, so hope this helps and i hope you come back with more questions,
remmeber if you try to rush this it will cause a lot of headaches and probably result in way more money spent than needed