I recently changed my santro's rear springs. The genuine springs have more turns, with lesser internal distance, but that is a drawback since we have bumpy roads and the springs fail to support the rear suspension. I recently bought springs from Montgomery road Lahore, they were i guess local Alto's springs they had a better height, better stiffness and a better internal distance between the turns, The whole thing costed me Rs. 1000/- with labor. I previously replaced the shocks as well but didnt find that much useful, this spring replacement did the job, now my car has a better stiffer suspension, and does not hit from beneath even with 3 persons at the rear seat on speed breakers. I have no experience of front shocks though, but i believe you wont be needing that after this work being done.
Regards,
Adeel