Henstone

I've ordered a Blitz nur spec R but I want to get the best out of it. Now I don't particuly (sp) want a de cat because of the mot issue. Now I know pretty much nothing about exhausts so that's why I need your help. Basically need the cheapest option that will pass the mot but give me more from my exhaust.
Any links to the stuff I need would be really appreciated aswell.
Thanks for any input.