That power supply you linked to is for a laptop. You need desktop power supplies. I have to assume you already have the 230W power supply and only need the 180W. You can get them pretty cheap on eBay:
180WTake a look at this
thread on how to set the jumpers on the motherboard.
You will also have to connect at least one of the cables from the motherboard to the card to get the power there.
The GeForce GTX 980 Ti’s TDP is 250W, according to Nvidia. But it never reaches that number under normal conditions so you should be fine with the 230W PS. Basically the jumpers tell the motherboard that the 230W PS is dedicated to the graphics card whilst the 180W is used for the rest of the computer.
If you need help with opening your PC, check out Welsh Gamers Youtube video's. They helped me a lot.