AGX's are only good for a 1" drop and a spring rate change of +10% over Stock. So in a way I wouldn't rec. them but if there for free you might as well take them. Also I advise you get springs that won't have you riding the bump stops on a rough rode. I personally think that the S-Chassis should be lowered at a 1:1 of Drop:Spring Rate increase. Simple terms for every 1.0" drop I'd rec. a 100% increase in spring rate. This pertains mostly to the front considering that front has about 1/3 of the travel the rear has so you should need to worry about the rear at all really.
S14 Stock Springs are 2.0kg F & R
1.0" Drop Should be in the area of 4.0kg to keep you off the Bump stops. You will none the less hit it should there be some kind of impurity in the road while taking a turn or while the suspension is compressing but to prevent you from "riding" them that is the ratio I have come up with.
I personally had Tanabe GF210 Springs on my 14 and they were horrible IMO. 1.5" Drop and the Front Spring rate was only 2.8kg. I was hitting the bump stop just about every time a decent size bump or change in the road occurd. Very irritating.
BUT, for something that's just going to be a daily you can get whatever you want. Those were just my recommendations.