FILE PHOTO: The logo of Boyu Capital is seen at the company's office in Hong Kong, Dec. 11, 2013. REUTERS/Tyrone Siu HONG KONG : Private equity firms Boyu Capital, Hillhouse Capital and BPEA EQT are among bidders vying for Longreach Group's Hong Kong-based medical device maker Quasar, three people with knowledge of the matter said. Longreach, an Asia-focused private equity firm, is targeting a valuation of as much as $600 million or more for the entire company, said one of the three sources and a separate person with knowledge of the transaction.