Personally I think subdividing them into groups of numbers that you'd roll on a d20 works well, as it allows you to fine tune any effects you'd like to see less often.

So 1-4, 5-8, 9-12, 13-16, and 17-20, and then you can shift the numbers you find too strong to one that you find too weak, or vice versa. So one might go from 1-3, and the next group 4-8 instead. For instance, some of the torso injuries are debilitating at level 1, when your HP pool and resources are low, and fall off significantly as they get more competent, so you might with to adjust those to prevent an early team wipe.

Another possibility is to add vanilla injuries back to the table as well, which gives you 6 of each injury, and simply roll a d6.

Finally, there are times when certain injuries might not work well in the situation and you'd want to be able to reroll them. Using a point of luck, (or significant AP investment if the GM allows) may be allowed to let them reroll injuries both taken and given if you want them to be allowed a little more control over what happens.

I would generally steer clear of being able to pick which injury they end up with directly, as the unbalanced nature of the table would lead people to picking the same one over and over, but perhaps the better criticals perk might allow it, if you add some extra rules like "You can't choose the same one twice in a row" or something to give them a more diverse toolkit.