I'm assuming you want to keep your CPU and board since they sound OK.

I've always thought Antec were a good brand, but have now made a mental note to avoid their really small cases.

The Sonata has had good reviews and I built a machine using this case for a friend. It was well made and had great little features like rubber hard drive mountings and a quality power supply to keep the noise down. Airflow was not bad. I'd recommend it, even though it is Antec again.

At work we have a fileserver in a Antec AMG???? case. It is excellent quality and airflow is great. Not the quietest case around but I'm sure a little bit of fiddling would fix that. It is also huge, which I'm guessing by the case you have at the moment is not something you would go for.

When you get a bigger case, you may want to think about a bigger heatsink to help wick away some heat with low speed fans.