Hi
Your m/board looks like standard connections.
The main power one from the PSU - does it look like this ?
There may be a separate 20 + 4 pin instead of 24
http://www.playtool.com/pages/psuconnectors/main24index.jpg
That PSU you are thinking of getting has SATA power connections.
Does the power connection to your hard drive look like this ?
Your m/board has both options. ( IDE and SATA )
http://www.playtool.com/pages/psuconnectors/sataindex.jpg
50Cm is about as long as you can get for the leads.
That PSU has 30Amps on the 12v rail - this will run any Video Card you decide to get.
I mentioned grounding[Earthing] the PSU to the case earlier.
You can do this with a wire from one of the screws on the PSU to one of the screws on the Case.
One thing about cheap PSUs.
PSUs in general are very inefficient and cheap ones are more so.
It says 500Watts but you may, over time, get considerably less.
They are also prone to failure long before an expensive one.
This said - if you want a cheap PSU that looks as if it will do the job :)
The black socket on the board next to the aluminium cooling fins is the PCIe x 16 socket for the video card.