which ex gasket set to get

I have always had great success with the Mr. Gasket flange/collector gskts. (That's all that was avail)
But I ALWAYS draw file the flanges flat/true, adding/removing material as nec. (Quality Modern headers are much better than the ones I started with in the 60's)
I learned early in my career, that customers don't like their new headers to leak, - so do it right the first time !
Seldom used gskts on cast exhaust manifolds, mating surfaces cleaned well .