Any thoughts on the Williams or Fenton cast exhaust manifolds or the stainless headers I am seeing around?

I like the reliability of the castings but I can't help but think the stainless tube headers are the way to go for me. Both stainless headers have bung fittings for my wide band o2 sensors and I think they would flow better. I am not looking for originality or that inline six rap. In fact I'm not fond of that sound and would like to avoid it.

So, with a cam I "think" the stainless headers are they way to go but I would love to hear some opinions.

Thanks!