PSU: "2x PCI Express 6 pinů"

This will only allow for one Graphics card. I made the same mistake on my rig, starting with a HD 5870 and planning to expand, because I thought "oh, I have 2 PCIe power connectors, that would suffice for two cards". Nope, one card needs two connectors already!

Also, I would not buy that much RAM from the start. You can surely save some Korunas when you buy one slower 1 GB bar. Apart from that, it doesn't look too bad, but it will probably take 6-12 months to pay it off completely. Although if you only plan on recuperating the cost of the GPU (that's the 200 USD, I guess) it will be quicker.