Your Dex and Vit are nice, but everything else is super low, especially crit chance, all res, and crit damage. I'm hardly a pro, but I think I can offer some help. Some builds have specific requirements, but I'm going to assume you're not working towards any of those. I can't really pick one piece of equipment that needs upgrading more than the others, so I'll go through them all and you can decide what you can upgrade easiest (or upgrade them all)
The stats you want to focus on are (in roughly the order of importance):
Move speed (caps at 25% - try to get 24%) - only available on boots and legendaries
Crit Chance - 30% is generally considered low, and 50% is a lot
Attack speed - 15% should be fairly achievable, although it can go over 45% for a 2h weapon
Crit damage - getting over 150% should be a good starting target
Dex - just get it really high
Vit (and life%) - I generally aim for at least 50% of dex
All resistance - 400 is a nice target
+Armor - Ideally your armor and all res should give the same damage reduction. In practice, just getting both as high as you can works well
Weapon damage - a weapon with at least 900DPS should be easy to get
Life on Hit or Life steal - Life on hit is better for quick hitting, low damage attacks, life steal is better for slower high damage attacks. Life regen isn't bad either, but less important
Optional: Pickup radius
I'm going to outline which pieces can have which stats, but the tl;dr version is to get the above stats as high as you can. How you do so is up to you, whether through farming, crafting, or searching the auction house. There are other nice stats to get, but I'm going to try to keep it simple.
Amulet and rings
Ideally get Crit chance, attack speed, and crit damage. Getting all three is very rare, but try to get at least two. Other nice stats to get are weapon damage, dex, vit, all res, life on hit or a socket.
Again, ideally get crit chance, attack speed and crit damage. You may have to settle for just two. Other good stats are all res, dex or vit.
Crit chance, all res, dex and vit. If you can't get all of them, crit chance is the most important, for the rest, get what you can. Alternatively, Lacuni Prowler's are great for the 12% movement speed and attack speed (and they can still get crit chance)
Crit chance, socket, all res, dex and vit. The Inna's radiance you have is really nice and you probably won't upgrade it any time soon, although some all resist would be good.
12% move speed. I don't even look at boots that don't have move speed. Additionally get all res, dex, and vit.
Dex, Vit, and all res. Simple. This is a good opportunity for pickup radius if you can get it.
Dex, Vit, all res, and life%. Almost as simple as the belt. Vit and life% are essentially interchangeable, but the best shoulders will have both. This is another good opportunity for pickup radius if you can get it.
Vit, Dex, all res, +armor, and 2 sockets. You probably won't get all of those. Pants are a good source of vit which is why I list it first. 1 point of allres is generally equal to 10 points of armor, and based on the gems you have in your equipment, one socket is worth 42 points of dex or vit.
Vit, Dex, all res, +armor, life%, 3 sockets. Everything I said for the pants applies here as well.
I've left the weapon last because it's the most likely to change with your build. Some skills such as seven-sided strike work better with slow 2h weapons, while other skills which require fast spirit generation tend to work better with fast dual wielded weapons. Your active skills suggest to me that you should dual wield, but your passives are aimed towards a 2h weapon so I'll leave that up to you (actually I just realized that you're using essence burn which works better with a 2h weapon).
Regardless, for your weapon, you want high base weapon damage, crit damage, life steal/life on hit, a socket, dex, and if possible attack speed. In general you want to put an emerald in the socket. Weapons are a poor choice for vit, since they tend to get upgraded or changed frequently. With that said, I would never turn down a good weapon because it had vit. Just try not to rely on the health it gives since you may find a better weapon without at some point.
Hopefully that helps, and hopefully I got everything right. I tried to keep it simple so I didn't even touch on things like stacking a single resist for use with One With Everything. The other thing I want to say is that you should probably reevaluate your mantra. Unless there's some specific reason you like Mantra of Retribution, any other mantra is superior.