I have the shop manuals for the 1987 Maxima and 1991 Stanza (identical layout and some interghangeable parts with 3rd gen Maxima). The manuals give very complete specs for the springs, dampening and sway bars.
For the '87 Max the spring rates and lengths for the GXE, SE and Station Wagon are all almost the same. (Very slight differences: the wagons had the higest rates and longest lengths (rear), SE's 1/8 shorter couple of pounds lighter than the GXE.) The sway bars are the same diameter. Springs in the front are constant rate and the ones in the back are progressive. The dampening rates for the struts are quite different, though: In the front the compression dampening is a little higher for the GXE than the SE, but the rebound is in between the SE values for Normal and Soft. In the back the compression and rebound dampening is just a little higher in the GXE than the Normal setting of the SE.
Could folks with shop manuals for the 3rd, 4th and 5th gen Maximas check to see what the real differences are between the GXE and SE models. It might be that all you have to do to get the same handling as a SE, with a GXE, is to get some decent after market struts.