Now just how much is it that your looking to spend on a skimmer? For is it that your a limit for what you can spend? Like I said, you are with a 180 tank and within the stand height that you have will find that you have far more of a selection in skimmers then I.
this skimmer is Price:$499.95
http://www.premiumaquatics.com/Merc...Product_Code=AM-71016&Category_Code=Aquamedic
You can as well if your no money issues buy the euroreef skimmer:
http://www.premiumaquatics.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=EURO
http://www.aquacave.com/EuroReefRCProteinSkimmers.aspx
You can as well take to use the ASM skimmer G4 plus
Or you can try and go with the ATI Bubble Master skimmer as I will.
http://www.reefgeek.com/filtration/Protein_Skimmers/ATI_Bubble_Master/
I had seen photos of this skimmer in action>
Or you could take a shot with the
AquaC which was as well suggested to me.
http://www.coralreefsupply.com/index.php?aquarium=skimmer_ac_ev
And the
MRC Protein Skimmers I not ever used myself, but do know that they are very good skimmers.
This might help you some:
http://reefkeeping.com/issues/2002-03/fm/index.php
http://www.aquacave.com/ProteinSkimmers.aspx
http://www.aquatictech.com/protein_skimmers.htm
So like I was saying, for your 180 your a greater number of choices to select from then I for my 240 with a lower height under the tanks stand. It all comes down to what you are willing to spend for I had my reasons to been willing to buy that $1,800+ skimmer for it would cost more still to change the tanks stand and it would had placed me in a longer drag to when I might begin enjoying these tanks, only if I no other choice would I do that.
The problem with some skimmers, your required to have the water level at a specific height for it to run as well as it should and all you need to be sure about is that your the height over the sump to get the skimmer of choice into your sump. The 60 gal tank sump that is in my 240 setup, I believe you could have something as that, but just be sure of your height space from the sump and over head of your stand (height that is).
Also, I have a number of Euroreef skimmers in my dry storage that one was only used for not even a month if that. I could see if the pump be still working, but the problem be is that you wouldn't even be able to fit this skimmer into your sump.
If this would work out for you and with others here who would vouch for you, I could then look to trust you that I send this skimmer to you that you pay for the shipping and if all is good with it, we can then discuss price.
I three euroreef in all just setting around.