[Cd]

As far as that 'Front bumper wedge' ( called an airdam ) that you referred to, you won't need one with a full bellypan, since the function of an airdam is to literally 'dam' the air coming under the car and move it to the sides of the car. ( Because the underside of the car is a huge mess for the airflow. )
The car will actually be sleeker without the airdam, and it still keeps its stock appearance.

Wheel covers aren't that big a deal on a car like yours because most cars like yours have pretty smooth wheels stock. You will be 'splitting hairs' and in the mountains where you live, you would be better off leaving the wheels the way they are for the brakes. ( brake heat going down the mountains )
Oh - and again, you will be keeping the stock appearance.