Turbulence set-up question

Pj

Hi I have a very simple geometry, a rectangular one with one inlet and an outlet. The fluid is air. I want to model turbulence. can u suggest which model. I was thinking standard k-e?? Are the default model constants sufficient or i should re-calculate? Also at the inlet, the values of k and e are 1? How do i find the right values for my problem? I know the velocity at the inlet. What other parameters should i consider while setting up?