If you want the geometry correct with a forester that's as low or lower than an impreza, then you'll need to swap the trailing arm brackets to gc8, rear roll bar brackets to gc8, rear gc8 sti pink arm kit, gc8 propshaft bearing housing, gc8 gearbox cradle, gc8 front subframe u bolts with subframe spacers removed, gc8 gear lever assembly, gc8 intercooler undertray, gc8 roll centre kit, plus other odds n sods Iv probably forgotten about.
I think Iv got the part number for the whiteline roll bar I got I look for u tomorrow 👍🏻