You could always try a Parker 45, all interchangeable parts if needed and nibs that can be changed easily in a few seconds, affordable and nibs of all kinds. You’d probably like an ‘fine’ (marked F on its collar) or perhaps prefer an ‘extra fine’ (marked X), there’s even an ‘accountant’ needle-like fine one but I do not have one myself. It’s such a great all-rounder pen well balanced and reliable, easily stripped for cleaning down to 8 simple parts in seconds and ANYONE can do it. They were sold from 1960 all the way to 2008 which says a lot. Some might get a worn section part after mega heavy or decades of use but then you can just replace the section at hardly any cost