H&R Springs - Very unstable
 

I recently bought a 1994 RX-7. The previous owner installed H&R springs on the stock shocks. The car sits nice and low. It's very pretty to look at, but the car is extremely stiff, bumpy, and almost unstable when it hits a rough patch on the road. I want to say it's because of the springs on the stock shocks, maybe they're blown out.

I understand that lowering a car reduces the suspensions travel length, and in turn absorbs less bump. I'm trying to find the softest suspension option that still allows me to have a lowered car. I guess you can call me old school, I enjoy a soft comfortable ride compared to shaking around like a ball bearing in a spray paint can.

I don't plan on going to the track, ever. I plan on turning the car into a highway beast. I'm strictly doing high speed straight pulls. Future plans are to swap a 2JZ-GTE into the car. Would it make more sense to get a spring/shock combo or should I stick with the complete coilover option?

Come to find the shocks were blown. Just installed a pair of BC Racing coilovers with a 10K front, 6k rear setup. On completely soft, the car feels like how it would have driven on stock suspension. Very soft, absorbs a lot of bumps, and very comfortable. With the shocks on complete stiff, the car tends to rattle around a bit, mostly because of all the plastics inside the car.

But for a driver like me, I'm looking for a comfortable ride, and this suspension has done that.

Looking for further updates as well. I'm considering Tien coilovers wondering if anybody has any input in this as well. I would also like soft comfortable ride but can be adjusted for occasional auto cross event.

Tein SS has a good reputation, though I have no personal experience.

I'm currently running Bilsteins together with a Ground Control coilover set-up, which is adjustable height for corner weighting. Shocks make a difference in ride quality. I used to run the GC's with GAB Super Rs which were adjustable. But even on the softest setting they were really harsh. I bought these Bilsteins used and not sure of the valving. They aren't adjustable but are firm while being much more livable. The Eibach springs are a small pain to change, even with a lift, but I have a couple extra sets with different rates depending on the use of the car. Coilovers also give me a little more room for wheel and tire...which are 17 X 9 + 38 with 255 40 17s.
FWIW, I also have an adjustable front sway-bar.