If you want to hide the in/out parts of the filter, there are a number of things you can do.
Spray on foam- This stuff can be found at Lowes/Homedepot/Menards as spray on insulation. I have this in the back of my reef tank, and it works great. I plan on using this on my next planted tank as well. You can use thread to anchor java moss to it and you'll have plants making the back wall of your tank in no time
Stacked rocks/fake plants- There are ways to aquascape your tank to hide the equipment. My favorite Idea is to get some of the long plastic plants and attach them to the tubing of your filter. Just make sure that it doesn't clog the input side.
Build an overflow- Depending on the level of effort and the CO2 requirements of the tank, you can build an overflow and have a little sump for your tank. If you're dosing CO2, I wouldn't do this however because of the increased gas exchange.
Do a closed loop system- This would involve drilling the tank. Another technique borrowed from reefers, this puts tubing directly attached to the walls of your tank, where a canister filter can be plumbed in-line
If you have any more questions about any of these Ideas, just let me know.