How big is the lawn? The best products --for instance--Heritage comes in golf course or acre size packages. And the cost is steep, real steep.
For home lawns or small jobs--you may need to use an Ortho, Bayer or Scotts product, immunox, Bayleton and propoconizole come to mind.
Be sure to read up on local information on controlling brown patch. We don't have the same diseases around here, but I have heard (on here) that you want to avoid fertilizer in hot weather, avoid water after 5 pm, and perhaps overseed with a disease resistant type of fescue.