need help deciding on cases

hey i was wondering if anyone would be able to help me out with my modular set up!
really new here in this fascinating world and still know close to nothing in terms of cases, power supplies etc (so all the important bits) - im quite happy with my module choices as i really like the busy circuits stuff and have researched these ones quite a bit,

im mainly unsure on what type of case and power supply stuff i should be considering?
and if i've missed any other important bits?

let me know if you can help! thank you :)

The general rule of thumb is to buy a much larger case than you think you need (this is good advice). I would recommend something that is at least 6u 104hp (like the TipTop Mantis). The Pittsburgh Modular cases are really nice too. Plenty of built-in power and connections. I'm a fan of threaded rails too. Sliding nuts are kind of a pain.
Though I don't know what kind of music you are interested in making, or if you already have any external gear to integrate with your proposed rack, you are missing quite a few things that would make this a fun setup. You are definitely going to need VCAs and some sort of sequencing option. You will probably want more modulation options than you currently have. And how will you listen to your results? Do you need a mixer and an I/O module with a headphone output and/or something to convert eurorack levels to line level?
I would recommend taking a long hard look through this forum to see previous recommendations on beginner setups. You will find a lot of questions, answers, and recommendations to make your journey into modular much more productive.
Have fun and good luck!

If you like ALM that much, why not just go for the Coupe:

https://busycircuits.com/coupe/

Seems pretty well thought out to me and a perfect beginner groove box with a nice voice - one could easily make whole tracks with that setup and a midi controller!

Stick an 0-coast next to it and you have a really nice best of many worlds system in a really small form factor.

Other than that I agree 100% with farkas, let us know what you would like to achieve and we can take it from there... there are unlimited options!