cusco, teins, buddyclub i have tried and were really harsh unless you live somewhere where you have really nice roads I won't really recommend them
the softest I have tried and used was tein super street which I think was mad for the streets
if you are looking at lowering springs I would suggest RS-R, Espelir, Sparco. Lowest lowering springs I have used was the Tanabe precedeo superdown lower springs which is very hard to find used