need help with question please
 

My brother is giving me a car. His old 1994 mazda mx6 v6. He said it needs a new harmonic balancer and some new headers. However he had an engine swap a while back with a Millenia Klze motor put in. I was wondering if it matters if i get the headers and harmonic balancer meant for a 1994 v6 mazda?. Also how much do you think it will cost for total replacement for both parts? including parts and labor? I found some headers here. the 2nd one. its black.
http://www.1motormart.com/unified/?N...667+11920+9215

and the harmonic balancer here: the third one on bottom.

http://www.1motormart.com/unified/?N...=Mazda&md=MX-6

if i get these, i just wanna make sure they will fit and work properly for the car. or should i find one for a millenia car? If so can you post links of places that are good to buy mazda parts from?

mazda millinia comes with a 2.5 and 2.3 so it depends what you have but if it is the 2.5 the enginr should be interchangable