i am looking for seforim \ rabbis that discuss the specific details of dikduk \ grammar as well as "explanations" of the different tagim and trop (tunes) for the Torah reading.
To check out the major early dikduk players see here: https://he.wikipedia.org/wiki/מדקדקי_העברית_בימי_הביניים
Similarly to examine trop / ta'amei hamikra see here: https://he.wikipedia.org/wiki/טעמי_המקרא, and for a good start, see R. Mordechai Breuer's section in the intro to דעת מקרא על בראשית, and then hop into his fairly well known sefer טעמי המקרא בכ"א ספרים ובספרי אמ"ת.
To begin your exploration into tagim, maybe see here: https://he.wikipedia.org/wiki/אותיות_סת"ם#התגים
Here is a nice short sefer on dikduk from the Ibn Ezra, which also discusses many of the great rabbis who preceded him in this topic.