Man wouldn't that be awesome if i were psychic lol. Na, was just assuming if you needed ram, didn't know you had some already. 2666 is fine. Regarding motherboards, the Z series support higher speed modules. The other chipset (H410 & B460) support up to 2933 which isn't a problem in your case. But if you want to run faster memory at some point or overclock cpu, Z490 is recommended. If you are planning on overclocking cpu, get the K version as it's multiplier is unlocked.
700w is fine IF the psu is good quality. If it's getting long in the tooth, 5+ years, might want to think about replacing it. Corsair and Seasonic to name a couple at least Gold rated. Higher quality units go on under Platinum then onward to Titanium but can cost an arm and possibly a leg too. Gold is fine.
Remember, modular psu cables aren't interchangeable. If you ever replace a modular psu, all cables, ATX, 12V, Sata (data cables are fine to reuse, just the sata power cable), PCie cables must all be replaced with cables the new psu comes with. Pinouts aren't standardized between brands and positive/negative pins from psu side of the cable can be in different spots increasing the chances of seeing a spectacular light show