The down pipes are different lengths both manifolds will bolt to any of the heads, but where the olive seal coupling is inder the car is at different points you either have to fit a complete 1600 exhaust or a complete 1300 exhaust.
BTB exhausts i think its 164 plus vat for a 1600 manifold.
A 1400 head is the same as a 1600 head as both engines are lean burn engines designed for low emissions and fuel economy. Try a 1300 head on your 1600 as it has larger arch way ports as it was designed for horse power potential for rallying. I think the valves are larger too.