If you want a smooth ride, do not get KYB struts. I had them on my Mazda 3, and took them off because they rode like crap. I went through
www.batinc.net and had them track down a set of Sachs Super Touring units from the UK. Same price as OEM, but should hold up a lot better.
The Sachs Super Touring are around $370. KYB, cheapest I have seen is around $240 shipped from Amazon.com. If interested, the part numbers for the Sachs Super Touring are 312824, 312825 for the fronts, and 312949 on the rear shocks. I spoke with Eric at
www.BATinc.net, he ordered them for me. For those of you not familiar with BATinc.net, it stands for British American Transfer. They are located in Florida, and handle performance parts for European based Fords, like Contour, Fiesta, Focus, and Merkur. I am running a set of Sachs Advantage (Sachs Super Gas on their site) for my Focus. Lifetime warranty, good price, great Struts/shocks, German feel, comfortable ride, good handling. Sachs-Boge are popular on VW, Saab, BMW, Audi, Mercedes, etc. The Sachs Super Touring are OEM replacements with a little more control and handling. They don't make the Advantage line for the Mazda 3.
They are special order for the Sachs. The OEM struts and shocks ride much better than the KYB units. The KYB's are very stiff on compression, and soft on rebound. Most European feeling dampers are softer on compression, and stiffer on rebound, keeping your tires in contact with the road. Personally, I was very disappointed with KYB's. Stiff on initial bumps, followed by float on dips.
I have about 6,000 miles on my Sachs Super Touring dampers so far. I have been very pleased with them, nice smooth ride, absorb bumps very well, but absolutely zero float. I think they actually have more feel than Koni FSD units do, and are much cheaper. I don't know about them for lowering springs, but maybe ok with Racing Beats. I am really impressed with their ability to negate bump steer, especially at higher speeds. The valving seems to firm up very nicely as needed, but body control is excellent. I am very pleased with the purchase, and would do it all over again if needed.