Questions - Need some input

looking at some octopus skimmers and they say they have metric plumbing what kind of issues will this cause. I dont ever recall seeing any metric pipe or adapters in the states

Looking for some input on a new skimmer have a old berlin style from my old set up but its not big enough for this 180. I havent had a reef tank up for awhile or one this size old was a 75gal so not up on all the new products. If some of you are useing any of the newer brands /types id love some suggestions

I stoped by a lfs and found these tanks today. I was just wondering if any one has seen these set ups before. I am in the process of making room in the basement for my fish room which has been kind of slow due to me being crippled up from a work injury in 08 so depending some on a bother in law that thinks im nuts. Taking out a 5 ft thick sandstone block and dirt support wall has really sucked, but since im now retired at 36 i need to full some time so i going to get back into it with both feet. ...