HE HAD BUNS OF STEEL… Advertising exec Sonya Duncan had no use for cowboys, except as filler for a pair of Rocky Ridge blue jeans. Just her luck that the man whose gorgeous rear fit the bill happened to be the genuine article, and no more cooperative than a steer at branding time. A WILL OF IRON… Clint Silver was no glossy poster boy, and the sooner Sonya Duncan figured that out, the better. He was a man whose blood ran hot just thinking about her. But she was a high-strung filly and he knew he was in for one tough ride before she'd let him love her. AND A HEART OF GOLD…