If you can spend Crowns, get the Immortal's Lore or the Road Warrior wands. They are currently the best for Critical and Block in the game at just about every level.
Another easy option is the crafted Celestia wands. The Celestian crafted wands give +20 Critical/Block, more or less. Zafaria doesn't have crafted wands, unfortunately.
If you're beyond level 70, give Atlantis a try. The Poseidon battle drops wands that range between +25 and +70 Critical, though the higher critical wands are Storm only and the lower are mostly Ice and Life. All of the other schools are in the middle, ranging from +40 to +65. Many of these wands also have some Block and an accuracy boost.
Last, if you happen to have any archmage one-shot dungeons that you won from boss battles, sometimes they drop good weapons. For example, the Meowiarity Archmage battle drops wands with +70 Critical (give or take, depending on which school). If you're not used to cheating bosses, go in with a friend. You only get one chance to run these dungeons.