If you want them now, your best bet for bred females calving this fall would be Kris Black's sale up in OK in early June. You can buy a bunch of them for reasonable money.
For spring calvers, you can find a bunch of good ones at a sale held during the Fort Worth Livestock Show. Females are there during the steer show and sell the last Sunday. You can find lots of heavy bred spring calving heifers and fall calving heifer pairs. We are taking 3 pens of fall calving pairs. We don't have anything for sale right now because we are already committed to taking them there.