If you take Biology & Chemisry, the biomedical professions (medicine, pharmacy, optometry, dentistry) would be options you could consider. Although not fully conversant with the arts, as far as I know, English A level would open the option of law.
Again, notwithstanding my limited experience in undergraduate requirements for IT/CS, I believe that you do not specifically need an IT-related A level to gain entry. Other evidence of skills/interest in IT should help e.g. ECDL, MOS exams, some interest in/knowledge of coding, etc.; (addition to my comments, perhaps from undergraduate CS students, would add real value to this post).