I’m generally a huge fan of Japanese pens. Although I own many Pilots, Platinums and Nakayas, my preference tends to be for Sailor, specifically the Realos despite their lower ink capacity. They’ve proved absolutely bullet-proof, and even basic Sailor nibs feel like nothing else, and come in some crazy variations (check out Cobra, King Eagle, Cross Concord etc).
That said, if I were you I wouldn’t think twice and would buy a
Conid Bulkfiller. I own quite a few and have been a huge fan since I bought one of the first prototype “First Production Run” Bulkfillers back in (I think) 2012. Since then I’ve added regulars, slimlines, serveral Kingsize and even have a custom pen made from some Omas celluloid I managed to source when the company went under.
They are simply the best engineered fountain pens ever made. Epic filling capacity, entirely self-serviceable, impervious to leaks because of the ingenious curved shut-off rod, don’t suffer from air-bubble blockages like most plunger fillers (looking at you Pilot 823 and Onoto), and a super-intricate mechanism that, once you get the hang of it, you can fill with your eyes closed.
The standard nibs by Bock (the same ones you’ll get on a Pelikan, just without the branding) are very good - especially the Titanium - but there is a whole community of modders, and even the company itself, that will let you fit both modern and vintage nibs from other manufacturers. My current favourite Bulkfiller sports a 1960s Mont-blanc 149 nib.
Whenever I travel, I do so with only Conids. They’re truly peerless.