As the title states, does it matter for an individual like me? I'm from a country that has no Japanese temple of any sort or a Pure Land sangha that I know of. While I am currently attending a Tibetan Buddhist temple, I'm very interested in Pure Land practices from Japan specifically.
I have a bit of an understanding between the difference between Jodo Shu and Jodo Shinshu but at the end of the day I cannot find any reason to differentiate between the two ultimately.
That said, does it matter which I subscribe to? I'm currently on the process of buying books, but I'm not sure if I should go for Shu or Shinshu or if I can mix it up lol.
Jodo Shu & Jodo Shinshu — does it matter?
Re: Jodo Shu & Jodo Shinshu — does it matter?
Try reading both, and Pure Land teachings broadly. Lots of great (free and legal) PDFs available online 
Over time, some teachers will seem to encourage your understanding and practice more. And you'll gain a sense of your tendencies, strengths, and limitations.
And since many teachers recommend reciting Amida Buddha's name, or at least thinking of that Buddha, you're always in good stead to make that your primary focus, whatever your present understanding.
For what it's worth, I would personally avoid books of a subjective, testimonial nature.
Other people's experiences are only useful to a point.
Also, the works of teachers themselves, both ancient and modern, tend to refresh the basics of Buddhism, positioning Pure Land practice within that framework.
Over time, some teachers will seem to encourage your understanding and practice more. And you'll gain a sense of your tendencies, strengths, and limitations.
And since many teachers recommend reciting Amida Buddha's name, or at least thinking of that Buddha, you're always in good stead to make that your primary focus, whatever your present understanding.
For what it's worth, I would personally avoid books of a subjective, testimonial nature.
Other people's experiences are only useful to a point.
Also, the works of teachers themselves, both ancient and modern, tend to refresh the basics of Buddhism, positioning Pure Land practice within that framework.
Namu Amida Butsu
Re: Jodo Shu & Jodo Shinshu — does it matter?
I come from a Jōdo Shinshū perspective and agree with Myoan.
After you have listened/read the Pure Land sūtras (since you have experience with Mahāyāna already and are tending towards Pure Land, you probably are already familiar with them), listen and read Hōnen and Shinran primarily.
For Shin, I would also suggest reading Rennyō's letters (Gobunsho) and "Thus Have I Heard" by Rennyō (Goichidaiki Kikigaki). Both will come across as repetitive at first, but you will begin to notice some of the things he repeatedly emphasises—these are essential points, in my opinion.
I also second Myoan's suggestion about avoiding contemporary testimonials until you are familiar enough with the tradition to be able to interpret them through the lens of Shinran/Rennyō and Hōnen.
There are, after all, points that Shinran and Rennyō emphasise that, while they are in Hōnen, are not emphasised in his writings and are not crucial to Jōdo Shū today. You will be drawn, naturally, to what suits your karma.
After you have listened/read the Pure Land sūtras (since you have experience with Mahāyāna already and are tending towards Pure Land, you probably are already familiar with them), listen and read Hōnen and Shinran primarily.
For Shin, I would also suggest reading Rennyō's letters (Gobunsho) and "Thus Have I Heard" by Rennyō (Goichidaiki Kikigaki). Both will come across as repetitive at first, but you will begin to notice some of the things he repeatedly emphasises—these are essential points, in my opinion.
I also second Myoan's suggestion about avoiding contemporary testimonials until you are familiar enough with the tradition to be able to interpret them through the lens of Shinran/Rennyō and Hōnen.
There are, after all, points that Shinran and Rennyō emphasise that, while they are in Hōnen, are not emphasised in his writings and are not crucial to Jōdo Shū today. You will be drawn, naturally, to what suits your karma.