Zach: sorry to hear about your buddy. As for the Tok - I do not believe there are any adjustable rear sights made for this pistol. Just about the only thing you can do with the sights on a Tok is to try and improve them to give you a better sight picture. I have known a few fellas to drill a small hole sideways through the front sight and use a blob of JB Weld to create a new front sight, one that is wider and a bit more 'square' - then they take a Swiss file to the rear sight and both open up and square off the rear sight notch. The rear notch can be outlined in white reflective paint and the rear of the front sight blade can be painted to match and give you a much better sight picture.
Although your Tok is M213, which never saw military service I think and was developed for the current high volume handgun market, it is still a Tokarev of near 1933 design and the sights reflect this - pretty similar to the 1911 earlier sights as well as those on the earlier P-35 High Powers. You might be able to find a set of MMC - Miniature Machine Company - sights that could dovetail in but I think you would have to pull the current rear sight, measure the base and see if MMC could make you a rear sight. You could also try that with a Nowak style sight to see if that helps or might fit but otherwise I think you may wind up working with whatcha got....
I also think the front sight on the 213s is the same as on the others - it's milled, not staked or dovetailed and I don't know if the slide is thick enough for a dovetail but good luck and let us know what you come up with.