Tosafot Shants are printed in the margins of Eduyot in the standard Vilna edition of the Talmud (counterintuitively, it isn't usually printed in editions of the Mishna). You can read it online here. His commentary to tractates in Zera'im, Middot and Tahorot is also printed with the Talmud.
The book Making it Work was released by Rabbi Ari Wasserman which contains discussions of many Halachic questions that arise in the modern workplace. The description is as follows:
The modern day workplace presents Jewish men and women with a constant array of obvious as well as subtle challenges, and now there is this go-to-guide for practical halachic ...
As noted by Dr. Shmuel in a comment, here are two recordings using the traditional Ashkenazi melody:
Modern Hebrew pronunciation - Cantor Moshe P. Weisblum, PhD
Ashkenazi pronunciation Part I Part II Part III Part IV - Rabbi Jeremy Wieder
You can read the hebrew version here. Keep in mind that Rabbi Hirsch wrote the original letter in Hebrew and as far as I know there is no German translation of that.
Everything from here and below is just lihagdil Torah viyadir.
You should be able to find the Hebrew version that professor Mordechai Breuer submitted for the Teves installment of Hamayan 5736....
As mentioned, Dotan does not include this pericope in his edition.
Here is an concordance of the Dotan and Baer-Strack edition. Notice that Baer-Strack section 61 is not included.
This is what he writes about the manuscripts in the English summary: