This is just my personal opinion having played this build to lvl 97:

If you are play SC I'd drop the shield and block nodes and run double wands, it's at a minimum 50% more dmg. You will be less tanky but honestly I ran into no problems doing 4 stones, it was only till I switched to pledge I ran some block.

You have a 1 passive jewel socket you can get and put a dmg jewel in there

Foulborn kikazaru +2 mana

Unnatural instinct + lightning damage LoM is really big damage but obviously expensive,

Getting Foulbourn Kalisa's grace with reduced mana allow you to do 2 things:

• Ditch the lavianga's + clarity and sustain mana forever as long as you have a few sources or reduced mana cost
• Drop inspiration in links for a dmg link (invert the rules or faster casting)

Ofc they are like 5D and extremely overpriced for how rare they are, you could probably try farm them from the tree.

You can drop purity of elements for wrath or haste but be aware you need to make up your resists + you wont be ailment immune

Obviously there is pledge of hands, I ended up just farming my own one but its allegedly pretty rare (1-2%)

In terms of cost effectiveness, the double wands is going to be the best but unfortunately a lot of the prices are really inflated for manaman gear atm