Built a Sump For $200

[MontanaRocknReefer]

I'm not drilling any holes in tank so what would I need to have a sump? There are two spaces under the stand divided by a piece of plywood. Each space under the tank is 2' x 2' x 3'. I have a 80 gallon reef tank(48" x 18" x 23"). I was thinking I could drill a hole through the center piece of plywood and have a refugium as well.
My son gave me a gift certificate for $200 at the LFS. Casey mentioned having a closed loop using the sump! I will take all ideas and suggestions and then decide what I will do! Maybe buy the two tanks and pumps first and get the other stuff as I go!
Will I be able to mount the Remora Pro Hang-on on the sump until I decide on what skimmer to get for the sump? This is all new to me so forgive my ignorance on this project. Thanks, Johnny Here is a couple of pics of the stand space!

[MontanaRocknReefer]

Here you can see the plywood that divides the two spaces and believe I can drill through this to hook up both tanks! Sound good!

[Geoff]

i am a little confused here. if you put a pump in a sump then it will be an open loop system, not a closed loop system. you can add a sump and/or refugium under the tank if you want. at least to hide the heater and the skimmer.

G~