3M Weatherstrip adhesive works good, be sure to follow the instructions and also clean both the headling housing and the rubber gasket. You can also replace the gaskets with common 1/4" half-round material.

The hood support clip is pretty common, so if you can't find one at your local auto parts place just take a stroll through your nearest pick-n-pull parts yard and grab one from a Rodeo or Trooper.