New Tank design

[BoSoxReefer]

Whats up people, I'm in the works of planning my new tank. I'm gonna be doing a 40 gallon, its a breeder I think I can't remember. (The tank is at my buddies house in his basement)
I am working on the design as far as what I want to do with the plumbing and the returns, and if I want to do a closed loop or not, and so on... I have played around with a lot of ideas and can't really settle on just one. I want to do a calfo style on the overlfow, but the over flow won't stretch across the whole back of the tank, maybe 3/4, centered. Any ideas on anything will be appreciated. Thanks.

[dendro982]

Here is link to Calfo style overflow threads with photos: http://archive.reefcentral.com/forums/showthread.php?s=&threadid=619976 , particularly http://archive.reefcentral.com/forums/showthread.php?threadid=473152 . Description, as you probably already know, is here: http://archive.reefcentral.com/forums/showthread.php?s=&threadid=554786 . For this the drilled tank is preferable. Also, there was discussed closed loop just for a flow purposes - if you need a very high flow rate, undesirable around the skimmer. Closed loop is generally preferred to powerheads, but I'm using 2 Seio 620 in 90g - so far, so good, but they take place inside the tank.
About flow: sorry, can't give links - but on thereeftanks.com is workshop on plumbing, with flow diagrams for general situations, or just search Galleries or Google images on "flow diagrams".
If you have are bottom tanks - there on Bare-bottom tanks forum, or here, on RC by advanced Google search.
If you are planning to keep sps - it will require more flow, light and filtration, if LPS or soft corals - less.
Also, again, gallery or Google for "40g breeder", "40 gal breeder tank" - it will show you particular solutions, already employed by other people. The long tanks, like this, require special approach - I have 20g long, quite a headache, comparing to a Nano-Cube.