SWTOR 7.0 Optimization of Unmoddable Gear

Game Update 7.0 Legacy of the Sith is live in Star Wars: The Old Republic, and along with this update has come changes to gearing. All level 80 gear will now be non-moddable gear, which means the stats of the gear will be locked to specific gear pieces.

According to a post by System Designer Bryant Wood on swtor.com, the changes have been made in order to give players a better experience and that if you follow the named set for your Combat Style you should see better performance for your class.
For example: If you play a Lightning Sorcerer you will be receiving Force-Lord's gear which will give the appropriate stats needed for this Combat Style.

However, if you are the kind of player who would like to have more control to optimize your stats, you can by combining gear pieces from different classes. Because all the gear is Adaptive, you can mix and match whatever pieces together you'd like.
For example: If you are a Damage Dealer, to ensure none of your attacks misses, you will need to have 110% Accuracy, which can only be achieved by combining various gear pieces from several classes.

How to get gear

I want to give fellow Content Creator Elssha a big shout-out for her graphs that shows where to buy and/or upgrade the various gear pieces, what currency you need, as well as how the stats will change as you increase your item rating. Be sure to read her comprehensive guide for more info!

You can earn gear through several sources: PvP, Conquest, Flashpoints and Operations.

For example: If you are strictly playing solo, you earn green Noble Decurion gear through Conquest with the highest item rating of 326. Higher rating, e.g. blue or purple gear, can only be earned through Group Content. Purple Rakata gear will only be available through Master Mode Operations.
Legendary Implants can be obtained by everyone, but it does require a subscription since it is artifact gear.

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You can acquire your first set of gear through completing the storyline on Manaan as you start 7.0 Legacy of the Sith that grants you a full set of green Decurion gear with item rating 318.

However, you can also purchase your first set of 320 Decurion with the Medal of Commendations currency and Credits in the Supply Area on the Fleet.
You can purchase your first set of green 316 Thyrsian gear with the Thyrsian Production Accelerant currency and Credits, if you prefer to not do any other content than PvP.

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As you upgrade your gear's item rating using the currencies you earn from the various game modes you play, your Stats will change.

For example: DPS and Healer gear will decrease in Endurance, but increases in Mastery, Power and Tertiary stats, which will be Critical, Accuracy or Alacrity.

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Tertiary Stats are needed to increase in damage, healing or defence. These stats will be helpful for solo-players, PvP-players and Raiders alike, but is especially necessary in more challenging content such as Master Mode Operations.

Below is a full list of 330 Rakata Gear and Tertiary Stats for Tanks, DPS and Healer classes.
Waist and Wrist pieces are not listed, since they have none of the relevant stats for optimization of your gear.

Tanks

DPS

Healers