Jim
I don't know which wood John is referring to as porous, but if it is the Wenge, I can tell you from experience that Wenge is not porous. Wenge is hard.
I made a large tack trunk out of Wenge and Brazilian Cherry, and that thing is very heavy. Empty it takes two fairly strong people to pick it up. I have also made smaller projects, and some picture frames from Wenge.
I used Seal-A-Cell, and Arm-R-Seal from General Finishes, as per their normal directions.
I think you should make the board out of Wenge also. It would be very striking.
Listen to your wife.
"The first thing you need to know, will likely be the last thing you learn." (Unknown)