|In general it looks good but as mentioned they do not give much details on power supply (make/model and other details) or even the brand of the graphics card (the models vary by who assembles them and even clock speeds vary).|
You might be better off with a local custom shop who can build you the equivalent to that one but give you more details in advance so you can ask about alternatives for some of the choices. Sometimes for a few dollars more you can upgrade a single item or two to make it better.
A cheap 800Watt power supply may have actually less available amperage on the 12Volt rail than a better quality 600Watt power supply which is needed if you are going to upgrade significantly the graphics card in the future. Also a cheap power supply if it is really bad can fail and even take out other expensive components. We are not saying that they do use cheap components where you cannot tell right away, but it is possible and is suspect when they do not say. Similarly, quality and important features differ between motherboards that can handle the same processor and without knowing what is included, you cannot tell if it really is a good buy and a good gaming machine or if it is an ordinary machine made up to appear to be a gaming machine.
You have to be a little bit crazy to keep you from going insane.