McMaster Carr has brass t's

91355K53

The fittings you listed are the right size but use brass.
Those are the hardest fittings to get at the local parts place. NAPA or Carquest will carry them.

You also need two 1/2 to 1/4 NPT reducers

And then two 1/4 male NPT to 5/16 hose to fit into the reducers.