Sooo, for your situation, I would suggest being reallyyy careful not to overspend on big brand names just cuz everyone else does!! I'm still kinda new to this but I was terrified of dropping my gear or running out of juice on my first trip. Honestly, instead of those expensive proprietary chargers, I found that the Anker 511 Charger Nano 3 30W paired with a Anker 541 USB-C to USB-C Cable 3ft is a total life-saver. It’s tiny and basically fits in a pocket, so you can just top off the battery during lunch. About the grip... I was actually worried a thumb grip might snag on things in ur bag? I went with a SmallRig Baseplate for Sony Alpha 7C II 4438 instead. It’s way cheaper than those pro plates and gives ur pinky a spot to rest so the camera feels way more secure. For the strap, I know that one brand is popular but the SmallRig Camera Shoulder Strap 2428 is fantastic for the price!! Japan is gonna be amazing, have the best time!! lol

Just found this thread! Before I give advice, curious about one thing: what's ur budget? I've been super happy with my setup and saved a ton skipping brands like Peak Design. - You looking for the absolute CHEAPEST power options?
- Need a grip that keeps the hot shoe open? Knowing ur limit helps... honestly, the SmallRig Thumb Grip for Sony Alpha 7C II is only $20 and works sooo well!

In my experience, that a7C II with the 40mm is basically the dream setup for Japan. I've tried many different combos over the years, and honestly, staying minimal is highkey the right move. I've been in your shoes before and here's how I see your options: Option A (Thumb Grip): I tried a grip from SmallRig for a bit, and while it helps the ergonomics, it kinda gets in the way of the dials. It also adds just enough height that it fits weirdly in smaller bags... super annoying. If youre trying to be stealthy, it just adds unnecessary bulk imo. Option B (The Strap): Peak Design is definitely the way to go here. I just use their thinnest strap and it’s plenty for that lightweight lens. The best part is being able to pop it off instantly when you're using a tripod or just want the camera in your hand. Its way more versatile than a fixed grip. Option C (Charging): For those long days of shooting, just get any compact PD power bank from Anker or a similar brand. The a7C II is sooo efficient that you can basically just top it off while you're grabbing ramen for lunch. It saves so much space compared to carrying a bunch of extra batteries and a bulky wall charger. Best choice? Stick with the thin strap and a tiny power brick. Skip the thumb grip cuz that 40mm lens is so light you dont really need the extra leverage anyway. Japan involves a ton of walking, so every gram counts!! Anyway, hope that helps and have the best time... lowkey jealous lol. 👍