These, to my knowledge, wont fit your zed as it will be a HR model, same as mine.
The 03-06 models that they all seem to be made for is the DE engine zeds with single intake etc.
If im honest I wouldnt be putting any ebay special products near my zed. It really is down to you get what you pay for as ive found out over my ownership so far. If you want decats ask some of the traders on here ... Abbey do Motordyne Art Pipe and Berks Decats ... The art pipes are expensive at £450-500 but better build quality and reviews than the ebays.
This is just my opinion ... I spent alot buying the zed I dont want to budget on parts ... even if that means saving for longer.
Id look into an upgraded Y pipe (Motordyne XYZ etc) then fit the resonated test pipes you are speaking off ... get a well known brand though as they will last longer and fit better.
Id also say buy my Nismo Intakes ... trust me you will never regret it
Chris