I am building a house which has interior (family room) and exterior (porch, front entry) wood ceilings, but I am struggling to find anything that works for me.

The ideal effect would be something like this:

The planks show no knots or grains but still maintains a natural wood feel. What is the material and how to achieve the effect?

I looked at cedars, and even the higher grade one has grains. After using oil-based stain, it looks like sth like this:

still too much grain on those and it doesn't look very clean.

Another possibility is to use something like BM's Arborcoat exterior wood stain, and to hide imperfections probably use solid paint. But it would look more like painted (might have to try it out).

Or, find more perfect, higher grade wood species, but I haven't been able to (the above one already costs >10$/sqft).

Any thoughts?