You say its for a 2001 plate Y reg, these are the start of the later 98hp silver top engine with the oil filter located in a different area at the front of the engine than the engine that the manifold your talking about was designed to fit onto to.
You can move the filter, loads of people have done it. Tbh though if it were me i would just get something that is actually supposed to fit your car and not have to worry about it once fitted.