Saccharum ravennae, Ravenna Grass AKA Hardy Pampas Grass, is tall with huge feathery plumes.

Any number of Miscanthus sinensis cultivars will fill your bill.

Calamagrostis x acutiflora 'Karl Foerster' is a very good one.

Stipa Gigantica has some very neat plumes. Don't know if Stipa varieties like OH though. You might check.

One of my books says zone 6, and one says zone 7 for Stipa gigantea.

I have a nearby nursery that might help.
http://www.amberwavegardens.com/pages/3/index.htm

Thanks everyone! I really like the feather reed grass & the hardy Pampas grass. Didnt know there was a hardy variety of that one! Now I have to decide how many I can fit in my garden... Thanks for the link too : )

Jen