All of these programs seem good. Each of them provides you with the necessary knowledge and skill that are appropriate to their respective fields:
The Bachelor of Science (Computer Science)/Bachelor of Laws is designed for students who are passionate about both computer science and law and have an interest in learning about the connection between the two fields.
The Bachelor of Commerce/Bachelor of Laws program enables students to establish and distinguish themselves in the business world while concurrently gaining a comprehensive legal education.
The Bachelor of Commerce/Bachelor of Science (Computer Science) is designed for students who are passionate about technology, including ways in which businesses utilise data and technology in order to create a competitive advantage.
Since you completed HSC Business Studies, you may wish to consider whether this subject enabled you to develop an interest in the business world. Subsequently, you could probably combine your interest in business with another interest, and hence choose one of:
The Bachelor of Commerce/Bachelor of Laws
The Bachelor of Commerce/Bachelor of Science (Computer Science)
To do what? Best by what metric? Pick what you want to do as a job. CS is bloody hard, and if you don't have a passion for it, you'll fail and fail again. Likewise for Law.