The best and cleanest installation will be to mount it in-dash.
The 2011 Tundra has a large factory radio. Replace it with a molded installation kit with two DIN sized openings. You can mount an aftermarket DIN stereo in the top slot and your 996T in the lower slot (or vise-versa). The 996T is a DIN radio (when the outer metal case it unscrewed) that will bolt directly into the installation kit.
Mount it this way and you'll have a very clean looking, fully installed system that is easily viewable and controllable from the drivers seat (and chances are you'll have better audio quality with an aftermarket stereo as well
). All your wiring will be hidden behind the dashboard panels and you won't have to give up any interior storage compartment space.
You mentioned that you are willing to drill; but since everything just bolts/plugs in, there should be no need to drill into anything. Good Luck