I'm looking for RallyCross setup, for the most part.
Well, why didn't you say so?
I'd go with the RS springs and struts, or maybe use some KYB AGXes stiffened about medium front & rear, along with a 13mm rear sway bar from an RS. I used the AGXes with STi V5/RA springs (around 30% or so stiffer than stock RS springs) and the 13mm rear bar at our first 2 rallyxes and liked that the best as far as car performance. (I finished 3rd and 1st overall at those, so I do kinda know what I'm talking about, too
) With the stock RS springs & struts it might be a little easier to bottom out the suspension, but the KYBs adjust the compression damping, so they might prevent that somewhat. The stock RS struts may not last very long if it's rutted.
The last rallyx, I had installed Konis in place of the AGXes, and busted the rears. Apparently they don't like lots of suspension travel or something.
Now I'm looking for a set of STi V5 struts to go with my V5/RA springs, and hoping they'll give me the performance and durability that I'm looking for, without going to "real" rally suspension.