There are lots of potential candidates. Take a look at the comparison chart, linked below, from Bluestem.ca, and see what tickles your fancy.

Keep in mind, almost any grass that tall, in your zone, will need to be cut to the ground in late winter - early spring, and won't regain it's full height until early summer at the earliest. Therefore, you'll have less than full screening for several months.

Here is a link that might be useful: Bluestem Ornamental Grass Chart