Similar to what I built except mine is much smaller. Seriously if you’re interested in not attracting a lot of attention a smaller package that fits in your shirt pocket (which mine does) and without all those large antenna... The small Nano with the factory optimized antenna is probably the better choice. In fact I’ve tried the large antenna and discovered it didn’t provide the performance of the much smaller package.  Have followed Darren Kitchen steady progress and have the utmost respect for those so dedicated at Hak5. I certainly have not improved upon their device but I’m thinking they might get a kick out of the unique application.  Not sure if posting in a public manner is correct but hopefully helpful.

This is more bulky than a laptop, it awesome but the reason you did it is kind of defeated .  Maybe go the 3d printed route and at least condense it into one enclosure with holes for the pineapple antenna's . With the only separate item being the k400r, or maybe one of those small handheld bluetooth keyboards.  I hear people complain about BT on the RPi all the time but I have never had a problem with it, but I can see why you went with the RF dongle instead..  I also have that keyboard, I have had a bunch of problems with it and I never even used it that much.  The 'o' key is dead and so is the right mouse button.  Still, nice build big thumbs up!