You'll want to get 10 7/8" sheets unless you can cut them down further, otherwise they might not fit into the wells.
I had to cut one of my spare arrows down to fit into the right arrow well, and it took about 20 minutes because I didn't want to mutilate it too severly.
I can get you my measurements Sunday afternoon, but it's not an actual official TX 1000, so the measurements will most definately be incorrect, especially since the arrow wells on mine are all slightly different sizes.
_________________
I used to be active here lol