@visakhv16, welcome to modular and Modular Grid!
A few comments:
-- the case size you picked is good, IMO big enough to be interesting, small enough to be portable, not cost a fortune, and not be completely baffling. I personally like Doepfer cases, and you can surely find those in a size similar to above.
-- regarding your goal "I'm trying to create a system which could act as a complex, evolving rhythm-generator/sequencer." IMO this is one of the harder things to pull off with some understanding and control of what's going on. SO I would say if that's what you want, patience and doing some "homework" will be very rewarding. See this post, the 3 links mentioned at the top https://www.modulargrid.net/e/forum/posts/index/9906 and also this post https://www.modulargrid.net/e/forum/posts/index/9928 ... those will have a lot of ideas and draft racks for you to explore!
-- your draft rack above has about as many complex modules put together as I've ever seen. I can tell you, as a 37 year musician and 15 year synthesist working with VSTs, getting into modular was still tough for me! It is hard enough to really understand a "basic" module, or function generator like Stages, let alone other modules which can be far far deeper and mysterious. This is not to say "avoid complex modules" -- but to point out it takes some real time, manual reading, experimentation, and practice to start to get some control over their behavior. Jim's advice (above) to do "minimum viable" or core system, then 1-2 modules at a time is good; that said, the urge to dive in (and maybe go overboard), I get it!
Good luck!