Hi everyone, I hope this question is allowed, if not please tell me and I'll remove the post!

So I have a Rhodia Goalbook A5 this year that I use for bullet journaling. I like it a lot, but being a grad student with definitely not enough freetime and all makes me feel a bit annoyed sometimes when having to create the next monthly spread and having a million other things to do, so I am considering switching things up to an easier approach.

I definitely want to keep a notebook again next year - I'll be starting my PhD in Physics in December, will be a TA again and am taking some courses (looking forward to learning Japanese next semester!), so I definitely need something to keep my structure.

As I am also an avid fountain pen user with a biiiiig love for all kinds of specialty inks I'd like to have something where I can use them properly (and show them off).

I have been looking at Hobonichis due to their structure and their fountain pen friendly paper. However, I am not quite sure which size is the best for me - the original seems small at A6, the weeks might not have enough space per day for me, also I do like the standard formats better. The Cousin would have the same format as my current journal, but I'm afraid that I "waste" too much space.

For reference, this is my current layout (see the last image for my weekly spread), I usually fill the complete page l and sometimes have to stick in sticky notes if there has been a lot that happened this week, even though I try to focus on the things that are most important. I have been bullet journaling only since this year really and I do hope I get to do more things again once this pandemic is finally over. I would use the journal for appointments and tasks as well as taking notes concerning my PhD or daily life I guess, and I do like designing pages/doodling a bit and writing poems/stories if I have the time.

Any recommendations (maybe there are some current grad students here even) on which size I should go for? Also advice on where to buy would be great, I'm from Germany so anything in Europe would be best.

Thanks to all of you in advance! :)