My advise is decide what you are looking to achieve with the car first. Then if its coilovers maybe have a ride in car with the brand you are looking at buying. Lots of members here running different coilovers for various reasons.

For me it was a case of wanting to get bigger rims (19") and reduce the height of the forester. I went with HSD coilovers after getting some good advise and feedback from others. I also selected coil springs with the rate that was best suited to comfort as well. A good reseller should be able to help you there. The other thing to consider is how just going low will effect the steering geometry of your car (handling). You will need at a minimum a good wheel alignment with some camber (read not bob jane spec alignment. You will also benefit from a Whiteline ALK to go with your new low stance.
My HSD are set soft and to be honest I never have any issues with ride comfort around town unless you hit a big pot hole and everyone will feel that. I am low but the car handles well. You are more than welcome to try me out for a test ride too. Hit me via pm.

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Funny looking German Subaru