I'm a fan of Redline fluids (I've used their 5W30 oil in my engine, 75W90 NS in my trans, and 75W90 in my rear differential), but I'm still not completely convinced that any kind of Shockproof should be used. I would use only 75W90 NS in the tranny because that's what's specifically formulated to be used in there. Since you have an STi, you'll need five quarts of it to ensure your transmission is full - it should hold four complete quarts and a little bit from the fifth quart.
07 WRX (Albins 5MT + Blouch 20G)
Jorge Carrillo Tuned (365 whp/340 wtq)