When I hear the farmers around me discussing grass seeding for erosion control, I think they have been discussing multi-grass blends?
I know a guy that got fined by the county for blowing dust after his irrigation well went dry and he just let his corn crop wither in place to cut his losses. He came back in with a drought-resistant prairie grass blend that worked out pretty well and gave him decent ground cover even though his place was in a mild drought for the first two years.
Also, if your project is for "erosion control", can you get some free or discounted seed from your county NRCS office? You might try giving them a call. Even if they can't help financially, they can probably give you some good recommendations for your particular climate and soil type.
(You should probably find out the name of your local conservation officer anyway. If you get a good one, they can be an invaluable resource.)
