decent shocks are about $400-550 a pair for front inserts, rear shocks are generally a little cheaper.
from what youre saying, and the rates youve chosen, maybe you should try bilsteins?
excel g's are a high quality japanese made replacement shock, with slightly firmer dampening than stock.
still, theyre always going to be borderline, even with your "soft" by ae86 enthusiasts standards spring rates... alot of knowledgeable people would still say thats over sprung.. And definitely no match for a purpose built coil over system, where the shock is valved to suit the spring perfectly (or close to).
pretty much the unfortunate reality is i think your just expecting too much, out of what can only be termed a budget set up.