You can;t run Spec.B Bilstein struts with springs intended for the base and limited. The base and limited came from the factory with KYB struts and shocks, which had a totally different spring setup. The only other available springs I know of are the JDM STi springs, commonly referred to here as "JDM pinks", which can be hard to come by.
I would suggest JDM Spec.b springs with saggy butt spacers because, well, there's not much out there
You can also take a look at OB2.5XT's setup, I believe he has King springs(rear only) and it leveled out much more nicely for him.