The stock radiator mount is retained. The Thunderhawk bracket slides over the stock piece, which creates a small, triangular-section box below the radiator for better strength.
The Thunderhawk bumper brace is designed to fit with most winches. The Polaris-style winch mount is the most common, and does fit with this bumper brace.
If you have any other questions, just give me a call, as these things are usually easier to discuss by phone that in repeated back-and-forth e-mails or postings.