There is a lot of good ammo out there, now. Realize that antelope are not hard to kill. Get a 150, or 165-grain bullet that shoots well and go hunt. You do not need bonded bullets etc., that are real expensive. I would start with cheap, soft-point ammo and work from there. Try Hornady American Whitetail ammo for sure, as it is probably one of the best deals going.
You have a great caliber and lots of choices to have fun with.
This is pretty much spot on.