Should I choose 16GB DDR5 or 32GB DDR4 for gaming?

Take the 16GB DDR5 kit. DDR5-6000 CL30 is fast enough that the lower latency and higher bandwidth matter more than double the RAM in most games. 16GB is still the sweet spot for gaming right now, and DDR5 motherboards give you an upgrade path to 32GB later. 32GB DDR4 is nice for heavy multitasking, but for pure gaming, DDR5 gives noticeably better frame times and 1% lows.