I planted oats late last year, did pretty well. One thing I noticed is, you need to plant it heavy. I did most of it at the 2-3 bu/A rate I would normally plant in the spring, when I got done I had a little seed left so I double-planted part of the field. The doubled-up part was much much better....maybe not 2x but probably 1.7x. With the cost of seed, it's alot of extra yield for not much $$. You don't need to be too concerned about frost, oats will take a quite a bit of cold before it dies, and the stubble will not overwinter like SRW would. Unless the ground really needs ripped, you could plant right into the oats stubble.

You might want to re-think the 'hay' idea. It will be tough to get something dry late in the year.