I'd say give the reverse etch a go and just keep testing the limits each time, you'll be there before you know it! 
Oh, I love doing reverse etches, but I think I will stick to big wide bold text and graphics! lol
You'd asked about the brushing on the Breakout Box....
Its just plain old 80 grit sand paper. But one thing I do is put a sheet of it down (rough side up) on the corner of my bench. Then I lay a 2X4 along one edge of the bench, OVER one end of the paper, and clamp both the paper and 2X4 to the bench.
Then I put the enclosure up against the 2X4, and drag the box along the paper. The 2X4 acts as a guide, and makes sure all the brush marks are running exactly the same. I occasionally unclamp, rotate the paper, and re-clamp, as needed. Often I will use up several sheets of paper on one enclosure. Oh, and I ALWAYS do the corners first. Just seems to work better that way for me.