Only display port? No go for me with 30" monitors that need dual link DVI. The active adapters are $100 and last only a few months before dying.
What active adapters are you using? The active adapters I got for my Crossfire HD 7950 and Crossfire HD 7970 setup only set me back $30 and have lasted for over 2 years. Got them back when I got my Crossfire HD 6950 setup and I am still using them on two different rigs.