Best in Slot. Firelands.

MMO-Champ is down and they have the most comprehensive loot list I've seen so I'll edit this up with the proper items and links as soon as curse stops having issues.

I need to do this for myself anyway so I might as well post on it and share. I'll start with Assassination because it is what I hope to be playing in FL, however I might play combat if it is better. Though I'll do that one another time. Non-base stat priorities are still the same as far as I know; yellow hit > spell hit > mastery > haste > expertise > crit > white hit.

Recently Rectangle (SW rogue) told me that Combat is currently outperforming Assassination on Patchwerk. I don't know what tools whoever is using to test that. It seems to me it would be hard to have all of the BiS gear even on PTR and do that kind of testing? Anyway he said they're quite close still, and it will of course be fight dependent. If there are adds or cleave ability, target swaps etc. We'll see when we get there I imagine, I'll build all 3 sets and test all 3 specs eventually as I always do.

4pc is going to be quite incredible so I would recommend getting that as quickly as you are able.

Helm - Dark Phoenix Helmet
Neck - Choker of the Vanquished Lord
Shoulders - Dark Phoenix Spaulders
Back - Dreadfire Drape
Chest - Breastplate of the Incendiary Soul
Bracer - Flamebinder Bracers
Gloves - Dark Phoenix Gloves
Belt - Flamebinding Girdle
Legs - Dark Phoenix Legguards
Boots - Treads of the Craft
Ring1 - Viridian Signet of the Avengers
Ring2 - Splintered Brimstone Seal
Trinket1 The Hungerer
Trinket2 - Matrix Restabilizer
Weapon1 - Feeding Frenzy>
Weapon2 - Entrail Disgorger
Ranged - Morningstar Shard

I find it odd that The Hungerer says equip proc, but also says 2 minute cooldown, was that a mistake or are they coming out and telling us the ICD for once? I'm going with the former.

For thrown, if you don't need to fan there is a FL trash bow that is considerably better.

If you have the Sinestra belt it is largely better than the new one from trash in FL one. At least until you get the item to upgrade it to its heroic version.

I'm also not sure what "random enchantment" the wrists off Alysrazor will be, so those may be added into the list over the current. I really hope these are for us since our other option is crit and expertise, vomit.

Now the 4pc + chest can easily be subbed with 4pc + Cinderweb Leggings if you can't manage the chest and happen upon the legs rather easily. The tier legs are better for Assassination than the chest however. Tier chest has expertise where as the tier legs have hit, that is the only difference really. Both "off" set pieces have mastery haste and red/red, red/yellow with +20agi bonuses. Depending how lucky you are it might be easiest to get the tier chest to make your 4pc fastest so just aim for 4pc however you can. After 4pc fit in your off piece choice once it is convenient to optimize. Another suitable substitute for your off set piece could be the crafted gloves, Clutches of Evil, but those take mats to craft, and a raid pattern drop perhaps. The gloves are mastery + haste with an agi bonus on a red socket so they are quite nice as well. Once you get into the heroic loot though the gloves don't have a heroic version since they are crafted.

I didn't take the item choices from anywhere, I used referencing from wowhead and mmmo-champ for the item stats and did my own evaluations.

-Correct

Edit: grammar, added items names in, removed roll over comment, added roll over links, thx Lega. Found a 2nd ring. Added trash bow for "thrown".