I saw your first post and thanks for the update it is great to see the progress. I think it looks great and I love these desks, so this is inspirational. 

I have a sheet of Lexan on the top of my desk for just that reason. Found it at my local hardware store (they cut it to my measurements). Lexan and its counterparts aren't exactly cheap, however. I had a 1/4" thick, 2.5' x 1' piece cut awhile back for another project and it cost about 18 bucks. So you don't get a lot for your money, but it certainly does the trick. If you want to decorate it, you could sand one side for a frosted effect--maybe. If you DO do the Lexan, you might not need the poly. For the feet, I'd probably go with the metal leaf to match the metal of the drawer pulls. Great project!