Hello.
Since last patch blizzard allowed us to use Ru cd-keys for Eu servers too ( before they was limited only to Ru servers ) .
Also they removed lang. limitation for wow client. Another words : you can buy Ru cd key and play on EU server with enGB wow client and Ru Cd-key
Where to buy ru cd key ?
There is many sites but they not accepting paypal. You have to find private seller, or friend who can buy it for u at ru shops and accept paypal. .
Almost all Ru users buying keys here : Plati.ru ( Exmple : http://www.plati.ru/asp/pay.asp?id_d=586038 )
Also game time on ru keys is cheaper than on eu keys.
60 days time card : http://www.plati.ru/asp/pay.asp?id_d=1690917 15.5 usd
What about IP ?
I guess they will watch IP location now for those keys. I recommend use Ru Proxy. Buy it or make it if u can.