It is good that you look forward to a university education.
Assuming that your "last stop" in education for now(not saying u
should stop at degree level, just for discussion here) is a degree,
i will advice you to choose your poly course based on what
you would like to do in university.
Since you have computer programming in mind, your course in
university could most probably be "Degree in Computer Science" or
even a "double degree", such as double degree in computer science
and business :
http://sce.ntu.edu.sg/Programmes/CurrentStudents/Undergraduate/Pages/nbsdd.aspx
My opinion is to go for a "full" technical diploma
instead of a "hybrid" course. I believe choosing a full
technical diploma helps you to prepare for university better than a
hybrid one, especially for demanding course like "computer science
or computer engineering"
As for your interest
in business, i will recommend that you do business modules as a
minor degree or do a double degree in computer science and
business. However it is going to be very difficult, but if
you are really interested, i will recommend that you do it at a
degree level.
The reason why i recommend this is because i strongly believe
the programming/computer science contents taught in the degree
level is very much heavier than that taught in the diploma level,
and having a strong foundation in poly will help you.
Thus, i will recommend you to go for a full diploma like diploma
in computer science or engineering, instead of IT with
business.
Now for the maths part, don't worry, engineering maths in poly
level is managable, and with your strong foundation in secondary
maths(E & A maths), i am sure you will do well.
The problem comes in when you start uni, the engineering maths
in uni is a lot more difficult than those in poly. The engineering
maths i learnt in uni is harder than the "higher engineering maths"
i took in poly.
Uni engineering maths will need a lot on your basics such as
E&A maths in secondary school, the concepts are not difficult,
the difficult are the tricks and manipulations that are built upon
those learnt in secondary school. You must know your E&A maths
very well, they will become a tool used everyday
Hope it helps, i went from Diploma EEE in SP to NTU EEE, still
an undergraduate. Please do well in poly, come to nus/ntu/better
unis, hope that you will get a degree smoothly