Send me a self-addressed box of at least 40 square feet and I'll be glad to send you some!
Seriously, first check the ph on it...chances are that it needs some lime if it has had horses on it for an extended period of time.
Once you get that established (and treated appropriately) go with winter wheat or rye.
Rye is hardy, it'll come up fast and thick and it's easy enough to broadcast by hand, although I'd recommend a mechanical broadcaster.
An acre and a half is much bigger than you think, once you get to working it by hand.
And don't forget the fertilizer.
Didn’t the horses “provide” the “fertilizer”?
“You need some Kudzu!”
Around here, any disturbed land will fill up automatically with Kudzu or more likely with Japanese Stilt Grass. :-)