I have not seen any plans, but I have seen a few of them on the web. Usually it involve a fish room behind the wall where the tank sits. You cut a hole (window) in the wall (being careful to re-frame the wall appropriately - that will be different if it is a load bearing wall vs non-load bearing wall.) Then you build a stand on the wall so that a fish tank will fit perfectly against the window. You frame out the hole on the display side so it looks good. The equipment for the tank & all maintenance is done in the fish room itself.
This is not a project for the inexperienced. However, if you have built a garage, or finished a basement, you cna tackle something like this.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.