Hi Mastro,
I drive an ''09 lib wagon which i use 5 days a week for work and carry around 250kg in the boot 24/7 + love driving through the hill at any chance i get
the standard suspension is ok but the rear just cant handle the added weight in the boot full time, and like you also wanted that lowered look.
I spent a fair bit of time looking at all different options for suspenion, coil overs or just spring replacment. As using the car mainly for work every day i didn't want anything too stiff but also couldnt be too soft! After looking at everything i ended up getting king spring low heavy dutys front and rear this dropped the hight all round appox 35-45mm (as low as STi pink springs) setting me back only $250- (springs only fitting +$$).
Driving around now is great, firm but not stupid and through the hills its real planted now.
dont get me wrong i've had tein hr coilovers in my silvia and bilstin coilovers in my skyline, you can never go past a set for adjustment, track use etc.
but for under the price of tein S tech spings i have heavy duty spings, white line rear sway bar and a car that now drives ace day to day and through the hills!
and fitting it all your self is just half the fun plus saves $$$