We did this hike 2 years ago. Great hike, enjoy.
We used the Wilderhouse shuttle for the beggining of the hike. We left our cars at the Portal and had them drive us to Giant Forest. That way you have a car when you finish and don't have to wait for a ride. I remember paying $80 per person for 6 people. Prices must have gone up. However, they were on time and reliable, at least when we used them.