Hi,
Triple science at GCSE is definatly an advantage as you cover more which helps you later at A level
You need to be getting A/A*'s in them
I would suggest picking other subjects that give you a broad range of skills but make sure these are not what the papers would call soft subjects, i supported by application with ICT German and Music.
Your English and English Literature should also be as strong and your maths no lower than a B, again prefrably at A/A*