yo, quick tip while i have a sec! honestly for your r6 ii, i recommend sticking with the Canon LP-E6NH Lithium-Ion Battery instead of generic ones. i tried a cheaper pack and it was super disappointing because the camera wouldnt let me use the fastest mechanical shutter speeds... basically wasted my money there. for the sd cards, a ProGrade Digital SDXC UHS-II V60 Gold 256GB is the sweet spot for 4k. i actually bought a Sony SF-G Tough Series UHS-II V90 128GB and it was crazy expensive for no real benefit since i think the r6 ii tops out around 340mbps anyway. also i had issues with a JJC Tempered Glass Screen Protector for Canon R6 Mark II being a bit too thick to close the screen flush... kinda annoying but idk. anyway v60 is definitely enough for travel! gl!

Ok so, jumping in here! Before I give advice, I'm curious about one thing: are you planning to record high-bitrate 4K60 video for long stretches, or is this trip mostly for stills with some casual clips?? Knowing your intent matters because mirrorless bitrates are way higher than old DSLRs. Basically, SD card ratings like V30 or V60 dictate the minimum sustained write speed. If the card is too slow, your video recording will just fail mid-shot. For most R6 II owners, V60 is the perfect middle ground. You get the speed for fast photo bursts without the high V90 price tag... it's literally the best value. I've been using the ProGrade Digital SDXC UHS-II V60 Gold 256GB for years and it works well for almost everything. Also, instead of buying a ton of spare batteries, grab a Anker 737 Power Bank PowerCore 24K. It supports PD charging, so you can top up the camera via USB-C during lunch. Ngl, it's a total life saver compared to carrying a dozen Canon LP-E6NH Lithium-Ion Battery packs. TL;DR: Share your shooting style! Generally, V60 cards and a PD power bank are the best value picks.

sooo congrats on the R6 II! i made that same jump from a DSLR a while back and honestly it's a total game changer but yeah the battery life is a bit of a shock at first lol. Basically mirrorless cameras are like tiny computers with screens that stay on the whole time youre shooting. That high-res EVF drains juice way faster than an old optical viewfinder ever did so you gotta be prepared. In my experience you really dont need to go overboard on the most expensive gear to get great results. Here is what i recommend:

• Definitely grab at least one extra Canon LP-E6NH Lithium-Ion Battery pack. I have tried many third-party ones and they are okay for backup but the genuine Canon ones are the only way to consistently get the full high-speed drive modes.
• For SD cards V60 is highkey the sweet spot for this camera. V90 is basically just burning money unless you are doing heavy professional cinema work. I personally use the Lexar Professional 1667x 128GB SDXC UHS-II Card V60 and it handles 4K video perfectly fine.
• Get a tempered glass protector like the ULBTER R6 Mark II Screen Protector 3 Pack Tempered Glass because that articulating screen is realy easy to scratch when youre flipping it around in a hurry. Its super easy to overspend but these few things will keep you shooting without issues. anyway hope that helps and good luck with the new rig!!