Buildapc

Should work fine. You'd just have to set the timings manually to run them all @3200 (one XMP profile runs at 3333MHz, while the other is set to 3200, even though the main timings and voltage appear to match otherwise). Or if you didn't want to bother with setting everything up manually you could probably run both with the second profile, which is 3000MHz on both kits.

Four sticks is usually harder on the memory controller than two, but you wouldn't be pushing high clocks on the memory anyway, so you'll probably be fine. That said, a new 32GB kit would be simpler in the long run, even though it's cheaper to just add a second kit.