Serious exhaust question, need somewhat expert advice please!!!!!!!

[Mr.Clerc]

NECESSARY PRE EXHAUST INFO:

So my plan is to build my S14 KA24DE motor in my S13 coupe to a DET. I have all the parts ready to order going with a megan turbo manifold and a S14 t28 turbo.

{{{{EXHAUST}}}}} i was thinking about fabricating my own. My dad's buddy is a pro welder, he welds his own race car frames and exhaust. Would it be more efficiant horsepower wise to do this, with the top of the line metals necessary?!? Or to go with like the top of the line HKS or whoever?

PLEASE: feel free to tell me if i look dumb for asking this question.