I really wouldn't recommend doing any BTECs to anyone who wants to do something academic in the future, as BTECs are almost always based on the 'softer' subjects.
I regret taking DiDA (ICT), even though like you, I got Distinctions. It was pretty much a waste of space, and I could have done something like French and History instead.
However, extra GCSEs can always be attained from your sixth form or college, although they usually only have the main three.
If you want to do something with business or art, then it's absolutely fine.