If I went to Sidney I would like to stay at Hotel Shangri-La because of its spectacular views to the Harbor, even though the rates are quite expensive.
I would like to visit the Opera House, Mrs Macquaire's Chair, the Royal Botanic Gardens and the Chinese Friendship Garden as well as Chinatown.
I would hire the car at Australia Car Rental as it offers rates from 275 AUD per week.
Concerning the Restaurant, I would choose Quay, which is the most valuated one at Tripadvisor Ratings.