Hey Gary, yes you'd have to remove the rear bumper to fit the clusters, but it's really not hard, either 3 or 5 screws and a few poppers and it's off
The HFC's are Powerflow or something, not Berks or Cobra etc.
The exhaust is awesome, not chav loud and has a great tone when you get up the rev range Infact, fitting both exhaust and HFC's at the same time would save you a load of hassle
Where abouts in NI are you? I'm in Portadown.