2001 Hyundai Tiburon Header

Hi. I own a hyundai coupe 1.6 16 valve 2001 RD2 with DOHC 4 cylinder engine. My manifold and cat are all connected as one item, The manifold needs replacing and someone told me stainless steel is far better.I have found 4-2-1 stainless headers but there only for the 2.0 litre models of my car. I spoke to a hyundai mechanic and he said the 1.6 and 2.0 4 cylinder DOHC engines are externally the same so the cylinder head and flange pattern are the same so all the headers will fit my 1.6 car. He said the only difference is the interal parts fo the engine like the injectors pistons etc. However the website that the headers are on, the people who are selling the headers say they are 99% sure the header will not fit my car. Hopefully you can help me out will this problem because I dont want to buy a header and find out it doesnt fit my car. Also if a header has 1 o2 bung for the sensor is it possible to put another hole in the header as my car has 2 sensors?