The 200tdi system is very restrictive...
I'd personnally....
Remove the large centre box, and remove the rear box (which is very restrictive does a number of tight turns)... and move the small remaining box to where the large main silencer used to be (or just leave it where it is)
You will find the engine more resposive (turbo will spin up faster due to less exhaust back pressure).
Noise wise, you will get a nice burble at idle, and a better noise under load (at full boost)... but the noise is not excessive.
The other option.... would be to run the Td (i.e. non Tdi) rear section...
This is what I ran on my 90" when it was a 200Tdi.
I removed the large centre box and just had the small, straight through, Td rear silencer (very different set up compared to a Td) - this exhaust is now on my mates 90" 200Tdi.
The third option....
Run a late Defender 300Tdi rear section... which is just a straight through pipe, with no silencers, which 'should' connect up the rear of your large centre silencer (basically replaces the rear exhaust including the 'over axle' bend).
To go one stage further, I'd cut out the large remaining centre silencer and replace with a smaller straight though one (either one from your existing exhaust or an after market one).
Either way, the system will not be over load... the turbo asks like a silencer... just in case your worried, you will have no problems come MOT time with just one silencer.
Ian