Exhaust upgrade Defender 90 Tdci 2010

I have a 2010 defender 90 2.4l. I wanna get a new exhaust to increase the performance but most of all the noise, just wanna here the defender a little bit more. I also still want it to pass MOT but not sure what options there are. Don't wanna spend more then about £400-600 max.
Any help would be great