Any of those rims should be fine provided you don't insist on some silly low spoke count build.

Avoid aluminum nipples; they're just weight-weenie fluff. They cost more and strip more easily than brass. Not worth the bother. I've built hundreds of wheels over the years and only use aluminum nipples if the customer insists on it despite my warnings.

There's nothing special about a welded seam. A properly built wheel is held together by the spokes. On weight-weenie wheels we used to take the pins out of pinned rims to save weight. Once built, the wheel works fine.