Coil over front springs

I have been autocrossing my Zink and the front end tends to push. I believe I need to put coil over springs on my front shocks but don't know what "rate" springs I should use. I want the front stiff. I see every rate font 95lbs up to 300+lbs.
I scaled my car a while back with me in it and the front weight was 250 and rear was 350 each wheel if that matters.
Suggestions?