It will only support up to 2 monitors. Crossfire usually only supports one, but it can go to 2 with the new drivers, I think.
Just get this and hook another 2 monitors to this.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125251
Just get this and hook another 2 monitors to this.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125251