5870's are sick, but they're all like $400 bucks +. And I don't think I need anything that crazy.
What about this one? http://www.newegg.com/Product/Product.aspx?Item=N82E16814150323
With the i5 system you have created, it feels like a complete waist putting in something so outdated.
I don't think the 64 bit driver issues people are having with the 5770's, are the normal.