hey apurva,

there is no as such difference between pursuing bcom+mba and bba+mba because both are integrated course and at  the end  you will be a MBA graduate but the thing is that bcom is a non professional degree and it includes more accounting and finance but BBA is a professional degree which lead you towards managerial and administration side.

for  long term goal i think  MBA is better backed up by a BBA background.

so here i would like to suggest you to go got BBA+MBA that would be a better option.

good luck!