Disintegrator STR based Caster

Main Spell:
Faster casting > Arcane surge > Iron will > Physical to lightning > Added fire

This skill will be spammed for getting charges, clearing trash, and general dps. L21 Arc is a great choice.

Alternate skill:
Iron will > Physical to lightning > Added fire > Controlled destruction.

This skill will be used for single target dps, or clearing support. Blade vortex is fantastic as it is a physical based skill and has a ton of single target damage. You can easily spam bv to 10 and use your other skill as well for added dps. The vaal variant is very strong for mapping.

Just add whatever support -- echo, efficacy, gmp, etc. Keep in mind that spell echo still counts as one skill use toward gaining charges.

Auras:
Enlighten > Wrath > Herald of purity > Herald of ash.

You will need the lab reservation enchant to run all 3 comfortably. If you don't have, just drop ash and enlighten.

Defenses:
Cast when damage taken > Immortal call > Increased duration > Vaal cold snap.

Keep immortal and cold snap at low level to trigger on lvl 1 CWDT.
The physical invulnerability is great as it helps mitigate damage from the degens and monsters.
Cold snap is a cool skill, as it will grant frenzy charges while mapping, but can be activated to instantly give frenzy for boss fights on demand.

Support:
Vengeance - the staff hits hard as a melee weapon, so you will get free life leech and mana leech, which allows completion of no regen maps without requiring mana flasks. Riposte is another option if you have high block.
Flame dash - simple mobility skill, doesn't need any links.
Lightning golem - cast speed.
Blood rage - gives frenzy charges. You don't need it, but it's cool to have.

While blood magic is an option, a ton of damage is lost, and it's really not worth it when a wrath watcher's eye can be had so easily. Any watcher's eye with mana leech from wrath is fine. Phys gain as lightning is a very nice bonus.

We can easily reach a large life pool (9000-11000) depending on our crafting luck and jewel choices. A large amount of regen / recovery from various sources completely overtakes the degeneration, and a large amount of block makes it nearly impossible to die in any fight.

Chest:

Elder armour chest. Astral is good, as it gives you the resist implicit. It's not too hard to roll high life and strength mods. The base can be difficult to get. In the mean time, it's fine to use kaom's or anything else.

Gloves:

The blasphemer glove gives a lot of life, needed dexterity, and effectiveness/damage with ailments. It's a common item and quite cheap. Elemental weakness is going to be the most helpful, but +1 gems is also nice. If you go with +1 gems, you can get a good damage boost from your aura/heralds and enlighten for a bigger mana pool.

Ring 1:

Mark of the shaper is a no-brainer, it gives a lot of damage and life.

Ring 2:

A coral is probably the best, for the extra life. Most of our resists can be easily had from crafted rares, tree nodes, or jewels. Try to get life, strength, spell damage, or resists. This is the hardest thing to craft, as most mods will be attack based.

Amulet:

Rare Elder amulet. Nothing fancy here, just an elder amulet with high ilvl to get a gain. Onyx is fine and easy to come by with the vendor recipe. The chaos gain is very nice, as is the fire. Some spell damage and cast speed will help a lot. It's difficult to get something perfect, but that's not required.

Unique elder amulet. Impresence can work, go with the lightning one, but you'll have to work around your gem sockets to blasphemy the conductivity.

Belt:

Rare elder belt. Gives a lot if you can get recovery, life, and strength. This is a bit hard to craft, and is not required.

Unique elder belt. Cyclopean coil is a great option and easy to come by. STR > INT > DEX. It gives a good boost to damage with dex being the lowest around 160.

Boots:

Elder armour boots. Not too hard to craft, just try to get movement speed, life, strength, and some resists. It is possible to get skill duration and dodge, which is a cool bonus.

Helmet:

Elder armour helmet. Gives a good amount of survivability. The elder base can have multiple damage to spell prefixes, physical damage to spells will be the best, but fire or chaos is also very good. You can get 2 spell damage prefixes, as well as 99 life. For suffixes, strength is good as it will give life, regen, and spell damage through iron will.

The only required jewel is a watcher's eye. You'll get 10+ sockets, which adds a lot of life, stats, and damage.
The red and blue chyula jewels grant a lot of survivability and damage with the added spell/attack block. You'll also get endurance and power charges, which helps a lot.

List of things to look for:
Increased max life, cast speed, spell damage, strength/dex, global physical damage

Quicksilver for mobility and curse immunity.
Rumi is great for added survivability.
Taste of hate gives good damage and survivaiblity.
Atziri gives good damage and survivability.
Blood gives alot of recovery when encountering maps that have recovery penalty mods.

Quartz or Sin's rebirth can work well too.

Oak offers the best damage and survivaiblity:
1% of Life Regenerated per second
2% additional Physical Damage Reduction
20% increased Physical Damage

Soul of Ralakesh helps mitigate the degen:
25% reduced damage over time while moving

Soul of Lunaris provides a lot of mitigation while mapping.
Soul of the Brine king is an OK option, but with a large life pool we will rarely be frozen or stunned.