When building a Myth box, like any other great engineering project, it's a good idea to stick with tools, techniques, and materials that are known to work. Yes, you sometimes need to adopt new methods or materials where nothing fulfills you needs, but you minimize those excursions into the unknown.
Having a "cool" keyboard is irrelevant because 99.99% of the time the keyboard is in the bottom drawer. I use my keyboard so little that its batteries will die of shelf-life before they're used up. Your "cool" keyboard is RF. That means you can't use a simple programmable remote to talk to its receiver -- you'll have to add a separate IR receiver and use lirc to control your Myth box over a remote control.
Had you used the keyboard suggested on this forum, you could have programmed a remote to talk directly to the receiver of the keyboard, bypassing both the separate IR receiver AND lirc, which isn't needed because your remote issues the same keyboard commands Myth already understands. Plus, it would have been less than half the cost of your cool keyboard (not even counting your IR receiver) AND its rubber feet would not fall off in the first week. (according to the one review on the site you linked
