Without getting overly complex, CL is cass latency. Lower is better, but there's a tradeoff with speed.
A 2666MHz kit should be available with CL13
A 3000MHz kit isn't going to do much better than CL15 in the typical consumer pricepoint.
Effectively, they'd be very similar.
Between your options presented, I think the Vengeange is a good choice.
If you're just looking to keep cost down, and don't care too much for aesthetics, this kit from RipjawsV kit is 2x8GB 3000MHz, CL15.... For $120
https://pcpartpicker.com/product/LhgPxr/gskill-memory-f43000c15d16gvrb
Or this Aegis kit, 2x8GB 3000MHz CL16 is $124..
https://pcpartpicker.com/product/FNprxr/gskill-aegis-16gb-2-x-8gb-ddr4-3000-memory-f43000c16d16gisb
Nowhere near as nice to look at though (subjectively) .