Helper springs or progressive
 

I was web surfing and noticed this site and it shows the non-adjustable ones have helper springs. Helper springs are the same price as new softer ones, so i'm trying to decide the best choice. My other idea was progressive HKS springs.

I have JIC Magic SF-1's with about 12k mi on them.

damper adjustibility has nothing to do with helper springs or not. In fact, the helper springs are providing the progressive effect.

When you have height adjustable coilovers the helper spring will be all open when the car is on the highest setup, Helper spring wil close more and more , the more you lower the car.

The helper spring adjust the inbound-outbound behaviour according to the stress you put on it (open/closed helper spring)

There is some great info on the site of this European manufacturer of coil over suspensions.

www.kw-gewindefahrwerke.de

It's also in english...

The spring on the damper is not a refference for how hard the kit is on your car, the damper is.
The springs will mostly be responsible for way the car behaves on the road.

our damper will be responsible for how hard the car feels.

In my opinion, a coil over set is useless if you don't have hardness adjustability, because you can not adjust your damper setting to the different height settings and according (helper)spring rates (affected by ride height). You then only depend on the way the damper manufacturer has calculated the gas/oil rates for your car.

Since I can't soften the dampening, I was hoping softer springs would compensate.