my car is shaking!! need help!!

[DJ Nismo]

my car shakes on rough roads, like left and right. when come to taking turns its very good. i was doing the oil change and i saw leaking rack and pinion. i think that might be the cause. also i am thinking about upgrading the suspension parts in the front. can any body give me a list of parts that i can install. i cant install coilovers because i dont have money for it yet. thnx in advance. also this is my first post, happy to be here. i just bought the car its a 89 s13 hatch.