Which exhaust gaskets?

I would go with the Victor-Reinz, simply because they're 1-piece with slots so you can hang them on the end studs before you start installing the manifolds. The Mahle gaskets get separated into pieces like the Fel-Pro. I can't speak for others, but I'll pay extra to avoid frustration in the garage.

Though they're not listed for the 318, I'd probably use Mahle part number 95095SG instead. More money, but the graphite gaskets work very well with exhaust manifolds. They're also a 1-piece design.

The Remflex gaskets are excellent, but might be overkill. Manifolds aren't that hard to seal if they're not cracked or badly warped.