i picked up 2 x Iwaki 30rxt's today to replace the eheim 1060's on my closed loops. i will be doing the plumbing for this using pressure piping and done as tidy as possible but not until later on as i want to consider my options. its most likely i wont use the SCWD's at this stage due to their design not fitting the needs of my setup (as pies says, great for smaller tanks say 3 or 4 foot). so, for anyone interested in buying a SCWD, Ive got a 2nd hand one for sale for $100 and brand new one for $115. PM if interested (brian, i think you were?)
Additionally, I am considering the oceans motions if it can be purchased at a good price. check this out for a professional setup!
http://www.oceansmotions.com/forum/viewtopic.php?t=222