There is no benefit in knuckles besides faster physical attacks

Sorcerer guide: Weapons and Equipment - As a wizard, you'll be using Avatar Gold up to 4 types of weapons. Staff, Dagger, Knuckle, and later on as a sorcerer, Orb.

Though you'll generally want to use a staff while performing magic, a Dagger + shield will work just as fine as well a little extra defense + physical offense never hurt anyone!

Knuckles however are not recommended. There's no benefit in knuckles besides faster physical attacks, but a dagger can do the job just as well as a knuckle. You also cannot use shields with knuckles so you lose out on potential defense, which a wizard most definitely needs.

The Privaring dagger, which adds a hefty amount of physical attack as well as boosting certain magical stats as well, should be a #1 priority to get as a dagger wielding wizard.

You can get one by hunting for Privaring urns off Privarings, or buying one off another player.

Note: Remember to get the Elias stone's skill point! If you are having difficulties hitting, I recommend suspending points in iron armor for sword mastery novice.

If you’re taking too much damage from physical attacks even with the most current armor, I'd recommend suspending points in sword mastery and putting them into Iron armor.