[The Wind Breezes]

For best ride quality I would keep spring rates and damping near stock. Replacing the stock bushings will go a long way toward getting rid of slop, but keep in mind the ride quality will at very best not improve.

If you're not doing track days, be realistic about the extent of how you'll push the car. I have a lot of track experience and surprised various, theoretically better, cars when my 135 was totally stock, runflats included. If you want to go fast in anything other than a straight line, mods won't help you whatsoever unless it's in the driver's seat. And it sounds like you're looking for comfort on long fast drives, so a good alignment, good (quiet) tires and stock suspension is probably what the doctor ordered. If you want to go really wild you can install air suspension, which is super freaking comfortable, but that will be a lot of money and / or effort.

Always keep in mind that your stock car will easily go fast enough to kill you or other road users, and / or get you put in jail or have your license taken away. You really don't need performance suspension mods for street driving.