Spectral 39 Shadow Priest
This was my first twink. He is an absolute terror in BG's.
Now building a 39 shadow priest does require gear trade offs. Unlike locks you just can't stack "of the Eagle" greens where there's no hands down blue or epic item (shoulders, wrist, hands) and spirit and int are all stats you must pay attention to.
If I had to do this toon over there are a few things I would have gotten for 39's that I am unable to go back and get now due to XP.
1. Pulsating Crystaline Shard for neck. This is a trade off item. I still believe the Triune Amulet or Necklace of Calisea are better 39 priest items. If you're looking for the DMG boost you may want it. I find 7 int more valuable for this class at 39 than 11 dmg.
2. Shoulder, yes I have of the Eagle and Owls for green shoulders. BoA shoulders will be your best bet. Unfortunately my main is Alliance so I'll never have them on my priest.
3. Chest. This is where I will differ with 99% of the people that have built priest twinks at 39. I will state emphatically that a Death's Head Vestment is the BEST item for a 39 priest with +6 all stats. Everyone seems to be against it and thinks Robes of the Lich or Magi are better. With a 3 stat dependent class I disagree. Good luck farming one of these up though; RFD trash blue drop, not a world drop.
4. Gloves; Revelosh of the Eagles or Owls. If I had to do it over again I'd get the Owls with 20 DMG. Unfortunately when I built this guy I decided that after putting stats pieces on my neck and chest without any DMG stats I needed the Black Mageweave. Not a bad choice on my part but I would do it different and get both.
Other than a couple of variables I might redo and some personal opinion differences with the majority I will say that my priest is almost perfectly geared for 39's.
I would not recommend Soulfrost in place of 40 spell power on your SoJ. You're still going to be healing yourself and FC's. Too much healing power to give up for 14 shadow damage.
I have over 27k lifetime kills and have represented my sever on PTR competition. If you visit the Emberstorm forums people will tell you this priest is a bastard to down and I frequently was number 1 on damage and killing blows even in matches that were twink heavy. Oh, this setup will destroy rogues too.