I am building a mining rig in this " guide"
https://en.bitcoin.it/wiki/Mining_rigCORSAIR Builder Series CX600 V2 600W , 80 PLUS Certified is recommend
I would power 2 5870 but this Power supply is only available for 90 dollars here is there a simmilar taht maybe is cheaper in europe?
Get real.
EVEN IF it is cheaper here, it has to be aif-frighted to the US and then it is more expensive. USD 90 is not high value, but weights a lot = high airfright rate. I doubt you can ship it for less than 15 to 20 usd.
or are you willing to wait for a ship to transport it over, which will take - hm - 4-6 weeks