Shaun Type R, is you ride a daily drive? Whats the plan for your ride?
Header/exhaust manifolds are somewhat application specific to the use of the engine.
So let us know your mods; main use of the car and we can better help.
If you are looking for a nice all around header/exhaust manifold, low cost solution to me would be the Blox Racing Tri-Y Header: USD $639
Just leave your oem cat in place until you decide on your header/exhaust manifold. Be more concerned with your cat back exhaust.
I have a 1.8 ITR engine; I was considering this but in the BLOX Big Tube [max flow] 4-2-1 version...still may pick one up too.