As far as I know, the main differences between the 19J exhaust and the 200 Tdi system (apart from the manifold/downpipe section) is the layout of the pipes and the method of joining them. 19J has the compression/overlap style while the 200 Tdi sections are joined by 3 x bolt flanges.
The 300 Tdi and 200 Tdi versions are as above, with different manifold/downpipe sections and the 300 Tdi style having 2 x bolt flanges at the joins.