I just picked up the R5 Mark II and I'm trying to figure out which memory cards to get. I shoot a mix of video (8K occasionally, mostly 4K) and high-speed bursts for wildlife. I've been looking at the CFexpress Type B cards, but the prices vary wildly. Are the expensive ones really worth it, or will mid-range cards handle everything fine? Also, should I get two matching cards or is it okay to mix speeds between the slots? What are you all using?