I bought it as a whole kit from here
http://www.flatironstuning.com/p-168...-gear-set.aspx because while there are part numbers online for what you need, there isn't really a definied list of everything you need. I wish I thought to write down what all was included in my box and you could probably take it to 1stsubaruparts.com and save yourself at least 100 dollars. Well see what I get back with the trans.
It swaps into all early WRX trans, I chose an 05 because I hear they're the strongest and they also need the least parts to upgraded to these gears. There's several threads on NASIOC about going to LGT gears for 1-2, I got 1-4 because my trans has a blown 3rd but other wise I'd have left it. The theory is that these gears are the same as V.6 STi Non-RA gears... No one can exactly prove that, but it's been confirmed they are identical as far as teeth thickness and gear ratios. Not doing the last gears keeps your 3.90 final drive.