Generally what do you mean by which institution produces excellent scoring students? If you don't make the effort to study then you won't get good grades at all frankly.

This is my own opinion as a current A-Level student. Do you have any budget constraints? If none then follow then crowd and go to popular institutions like Taylors/Inti or the like. Anywhere will do as long you bother to make the effort.

What the above poster written is correct, Taylors have the highest fees currently for A Lvs. As for the lowest, AFAIK the lowest I've seen is RM5.8k or so for the full course excluding exam fees which are about RM1000+/- for 3 A level subjects.

Usually for medicine, chemistry and physics combination will do, however if you want to take up biology and chemistry combo that will do as well as long you have chemistry.