A new name-related quandary in transliteration

As you may have heard, as of October 17th Amelia and I are both changing our last name to Birch, and for the first time in my life I'm faced with an option: do I want a middle name? Being as interested as I am in naming conventions, it seems like an opportunity in self-identification way too fantastic to pass up; but it does also bring up this question of choosing said middle name.

Since I'm giving up Brandt, my connection to my Jewish/Yiddish heritage, I've been thinking about...something I don't know how to write, which is indeed the main point of this post, so just pretend for the moment that there's a name here...almost since the inception of discussion about this whole Birch idea. This is my paternal grandfather's original Yiddish name, before he gave it up to avoid persecution in post-WWII Poland, and also the name of his uncle who protected him and helped him survive in hiding during the Holocaust and was killed in Russian-German crossfire in the war's final days. It's a good name, and it makes me feel proud to imagine carrying it around with me.

So that's not the problem; no, the problem is one of spelling. In various systems of transliteration, the name is as follows:

[ˈɡɛɾʃən] or [ˈɡɛɾʃn̩] - IPA
[`gErS@n] or [`gErS=n] - SAMPA
[gārshŭn] - American dictionary phonetics
[GAIR-shin] - Phrasebook English

I just discovered this afternoon that this is actually a Biblical name, and as such in English is generally spelled Gershon (from Hebrew גרשון, "gršun" in transliteration). When my grandfather learned to write, though, he was taught to spell his name גערשן, "geršn," which represents the way it's actually pronounced in Yiddish (Yiddish, unlike Hebrew, uses a phonemic writing system). Now, if I were going to transcribe the Yiddish גערשן into English, the standard system would give me Gershn. And just to throw some further confusion into the mix: since we're talking about Polish Jews, another possibility is the standard Polish transliteration of this name: Gerszon.

So which should it be? Gershon, as the English (and even the educated Yiddish) print standard? Or Gershn as representative of the way it was apparently written in the community of farmers in Eastern Poland to whom I'm paying homage in adopting this name? Or something else? Any input would be very much appreciated.