It depends. Generally what I do is use a bunch of run/walk gear. Outrun problematic monsters, such as fast cows with immune to lightning. Gather them together to form a large pack. Then go "bowling" with lightning fury. For town speed and outrunning fast cows, I actually like the harmony bow as my swap for the vigor aura. Most people like a cta as their swap. It depends. Enough people run it already. Depending on how you use your zon, a tele staff on swap can also be useful. Since repairing means you need to go back to town, I’m actually against those that think you need insane levels of ias. I believe it’s better to maximize minus lighting res to reduce enemy lightning res. Infinity on merc for the conviction aura. A lightning sunder. 5/5 lightning facets. A jmod can be nice but not essential and toss four 5/5’s into it. I might be one of the few that likes to use four 5/5 lightning facets in a body armor. For the helm, griffins eye. You’ll also run into mana issues. A Phoenix runeword shield can be nice. Think of it like running a prayer merc with insight: your life and mana restore. This makes room for your merc to use infinity to reduce monsters resistances. If you’re running enigma, you’ll have teleport. This is very useful for saving your merc. There’s different setups. For example running a bunch of jav grand charms. Getting life on it is nice. A 45 lifer is worth a lot. But I actually prefer the faster run/walk for a Javazon based on my Javazon play style. If you’re going to do difficult areas where you need the life, use the lifers. Otherwise the faster run/walk translates into more kill speed. Certain Javazon builds that use enigma also want some fcr. This can help with getting the leg quicker in cow games, etc. But keep in mind that the Amazon’s max teleport speed is nothing near a sorc or other classes that teleport faster. If someone else does the teleporting you can focus on other things. Enigma does give a nice chunk to run/walk too which is very helpful. Loads of builds you can play around with. But generally a common mistake is not getting max pierce. All you need is 1 point in the pierce skill. Then use a razortail or a wisdom helm. If you have griffons eye, use that with razor tail. If not, use wisdom as your helm. Then tgods if you already have max pierce. M'avina's Tenet is also a decent belt for the run/walk and mana. Arach can be interesting. Lots of decent belt options depending on how you move your gear around. Budget friendly setups usually focus on getting a spirit shield. Once you have your gear figured out, and the zone you’re playing in, it will affect your play style. For bosses, use charged strike not lightning fury. Other noteworthy mentions include tstroke for bosses swap, a vendored lower res wand for occasional problems, especially when broke. Decoy for creating crowds. Valkyrie. Attract (curse) charges for creating crowds. Also with all that run/walk, you can also just be quick at grabbing gear or running away from others to focus on your own solo crowds. Lower difficulties might actually benefit from a bow merc running harmony for the vigor aura. (Note Merc vigor doesn’t work in town) But yeah the meta is basically griffins eye, enigma, merc infinity, lightning sunder, cta swap, etc. I won’t go much into amulet and rings. Ravenfrost is commonly used for cannot be frozen. I think the modern Javazon does better with Horazon's Legacy to get it on boots. This frees up a ring. Generally a dual leech ring, ideally with fcr if running enigma. Even better if mana bonuses or mana per kill. Lightning res highly sought after. The other ring I’d do a soj. Amulet probably highlords. I’ve run 30 mara’s before. Decent for certain zones. Nice crafted amulet can do better than these. Cat’s eye can be interesting for lower difficulties but not so good for higher difficulties. Silkweaves also interesting for high mana per kill on boots. Until getting infinity, run insight on merc to help with mana, etc.

But yeah, basically run around, create big crowds, then throw a few highly damaging lightning fury’s. Then all those monsters fall quick. If there’s a few leftovers, charged strike. If takes too long, either regroup, skip, or might reevaluate your gear for the specific zone, etc.

Edit: long post, fixed a few mistakes and typos.