in your country, its different, the f28 was awd, and such in europe. It was available as fwd in africa for some reason.
For the most part it will be different gearing, and size. But both will be a 6 speed and will bolt up to the bell housing.
The diff might be different sizes, as well the overall strength of the engine. (I can only speculate for the most part, as i have not seen an f28 in person, and i have only read about and driven the m32, not torn it apart.)
f28 stuff:
F28 Into Astra G
the m32 is also in african opels though.. i just found one maybe.