Aggieland is a good one full of Ags and there are a few others that war more frequent than others. Aggieland we war twice a week. It also depends on how strong you are as a player on which clans will be best to join.
I'm in a clan with about half super serious and half not so serious that launches saturday pm and then right away monday pm then rests.
Trying to pickup one more serious war clan, but timing is going to be difficult. I have one that's sort of semi-serious that works fine for a thursday am start then I usually split friday by noon.