I found a company in Pennsylvania that sells native seed mixes that may be suitable for your needs. It would probably be a good idea to contact them to find out what seed mix would be best for you.

Here is a link that might be useful: Ernst Seed

I also have a wet area that I am trying to reclaim. At first I thought it would be hard to find plants that will like to be wet for long periods. But doing research, found there are quite a lot of perennials that will work. Try the following that just come to mind right noew.

Aruncus-Goats Beard
Aster-New England
Boltonia asteroids
Eupatorium(Joe Pye Weed)
Iris siberiaca
Helenium-Sneezeweed
Helianthus maximilliani
Hibiscus moschatus
Rudbeckia-Black eyed susan

and I'm sure there are more. These all are growing in my Z4a Mn wet spot so are quite hardy.
Don't try to just scatter seeds and expect them to grow in place of weeds. You will need to set up a nursery and germinate the seeds, then pamper them until they are large enough to fight on their own.

For a durable cool-season native grass, you might want to consider Canadian wild rye or red fescue. No personal experience with either, but the species descriptions I've found seem to match what you're looking for.

Thanks for this.

After some more research, I can be more specific. I want a sod type grass with deep roots, that grows fast enough and is hardy enough to stand the trampling of poultry. It should do well in a heavily nitrogen environment.

Red fescue might fit this, though I'm not sure if it is vigorous enough.

Prices that I've found for native wetland grass/wildflower seed mixes are astronomical ($125/lb), so I'm interested in economical ideas and sources.

Thank you,

--Jonathan

Have you looked at Prairie Moon Nursery? A pound of seed should easily cover 2500 square feet, BTW. You probably need less than a pound.