Depends what your future plans are. A front facing intake manifold for the NA does look nice, but because of the design unless your forced induction you don't get ANY benifits, and might even loose power.
The OEM intake has a torque increase valve, which will also be removed. Because of the way the air is split in the OEM manifold, your stuck with replacements unless you have the same design with a different manifold, which would be pointless.
David P has a different over head intake manifold, but thats a custom made unit. ITB's are not worth the money. They sound and look pretty but bang for buck, your be down on power compared to an NA-T and will cost twice as well.
What is the problem your trying to solve? For what reason do you want to replace it.