Looks like it could be DIY, so how do I replicate this overflow kit?

it looks like after a trip to homedepot and you would be set.. might need to let it sit overnight with some silicone to get it sealed up tight or whatever.. but it should be a pretty easy diy

The drain looks like a Durso standpipe. Check out this link and build your own. It should be less than $20 in supplies, all available at Lowes or Home Depot. It lists all the sizes and parts you'll need.

http://www.dursostandpipes.com/BuildYourOwn/tabid/54/Default.aspx

Also, I wouldn't have those lower inlets on the overflow box, if you were planning to copy that design. In the event of a power outlet or pump failure, water will continue to drain from your tank into your sump until it reaches the lowest inlet. That means water all over your floor.

Shoot me a PM if you need any help building the Durso standpipes. It is easy though. Another bonus is that they're super quiet. Good luck.


***EDITED TO ADD***
The link talks about gluing and teflon tape. I used slip fit PVC parts and didn't glue or tape anything.

The lower inlets wont drain your tanks,those are the standard aga overflow boxes look at the diagram water still has to go over the top.

the durso standpipe is really easy to make,just need 2 9o deg elbows and some pvc.I used a bit of teflon tape to hold it together,instead of glue just in case I had to take it apart.