Reason being is that i just want to slap on the Greddy turbo kit but they don't make it for the A6. Or is it just easier to just get the Z6 motor first?

 

the biggest factor determining which turbo kit works with what motor is the exhaust manifold. the d16a6 and d16z6 have the same bolt pattern so the manifold will fit. Of course, you are going to have to modify the charge pipes are they are designed for a 92-95 car.

 

with some mods on the intake then yeah

 

Ok i guess i'm better off buying an EG instead of an EF so i can slap on that kit.

 

You can find parts to make it work with either the z6 or the a6... I am getting ready to put a greddy turbo kit on my a6 as soon as I sell my d16z6/y8 internals https://honda-tech.com/zerothread?id=962350