Help, please

[animallover]

Hi again!
Brian, the link you sent me on the sump is EXACTLY what I have. I;m not sure I understand, why should I get rid of the trays and wheel, and why get rid of skimmer (any suggestions as to what to get?) I wouldn't have a clue as to where to go from here to replace my sump system? I was told at one LFS that most find it hard to get their nitrate levels below 40-50ppm? He felt that since most of my parameters are good that my nitrates being at 20-30 was good. Because I'm quite new at this, I tend to believe what people in the business tell me. So if this info is bunk, I wouldn't know. You guys are scaring me a bit by telling me to get rid of my sump setup. I honestly don't know where to go from here. Thank you all again, as I truly appreciate the advice. Thanks to "fishytime" for taking your extra time with me!
PS I have about 20-25 pounds of live rock