If your goal is better response at turn in, add some toe out. Be aware this will eat tires quicker though and be slightly disconcerting under braking. I don't think any of the kits are going to significantly change turn in. They mostly effect the outside suspension after it is compressed to some degree.
If your goal is to reduce mid corner understeer... Unfortunately there is no cost effective way to change to unequal length A arms in the front which is probably the only true non band-aid.
Your stock struts make caster/camber plates basically useless, so no joy moving the top of the strut.
The ALK will help Caster and roll center a bit by pushing the rear or the front A arm down and out which pushes the lower ball forward and out.
The taller lower ball and tie rod ends known which WL calls the roll center kit change the compression/roll camber and bump steer curves by increasing the distance from the arm to both balls. The lower ball change is beneficial as long as you can keep the arm below horizontal by some means. As soon as it goes past horizontal, it exacerbates the original issue, and camber goes positive even faster.
People put 32mm front bars on stock Imprezas to try and keep the lower arms from going past horizontal. The increased grip due to retained camber more than compensates for the increased weight transfer.
You really are stuck between a rock and a hard place. The WL RC kit may get your camber curve back close to stock under DD situations, but may hurt you under extreme handling like autocross unless you control roll better.
I just thought of something. you may be a good candidate for the Praxis air suspension system given your requirements especially if combined with the ball relocaters. While it is less than ideal, as you lower the suspension, it will increase toe out, and increase spring rates. I am guessing it is way out of budget though.