As stated a TD exhaust should be fine. On Friday I completed my new exhaust system, it was cobbled together a couple of years ago when I dropped the 200tdi in, with no silencers and a nice exit out of the side - just to the right of the drivers door. I have now chopped up the front and intermediate pipes from a standard 200tdi Defender system to fit the steve parker like down pipe. There are two flex joins and two silencers in the system and it is a hell of a lot better than it was when it was straight through. Much quieter too and a much improved turbo response.
-Tom