Auto Parts: Auto suspension, hypercoil springs, flim flam

Question
I own a 95 Toyota Supra TT that I have tried 4 different suspensions on and I still don't like it.  Everything I have tried thus far (non were OEM) has been brutal if you hit bumps in terms of the stiffness and the noise. On smooth roads...fine.  It came with Eibach springs and Koni Shocks.  I then tried Megan coilovers.  My 3rd attempt was Hypercoil springs and Bilstean shocks.  Lastly I now have Hypermax III coilovers on my car.  The Megan's and the Hypermax both have adjustable shocks but to no avail.  When you hit even medium bumps/cracks in the pavement it sounds and feels like you are metal on metal.  More like you are in a creaky panel van instead of a sedan sports car.  In addition none of the above mentioned suspensions were good at keeping my tires in contact with the pavement when you are accelerating over bumps.  Any suggestions or comments?  Thanks!

Answer
    I've run into problems like this many times.  Here's my take on the subject:  All of these spring packages you've been trying are designed either for the race track or drifting.  Both of these activities are done on very smooth surfaces.  These companies put their names on the race cars and make their money be selling the products to folks who are going to drive them on the street.  Basically they are conducting a flim-flam operation to make their customers think that their cars will handle better on the street with these products, which they will not.  Recent problems aside, have you any idea how much money Toyota spends to develop the chassis of a car like this?  It's plenty.  Here's my opinion on improving handling of these cars.  Keep the OE springs, maybe even go to the springs used on the lower-performance standard model.  Use the heaviest anti-roll bars available, making sure that they are matched front and rear for use together.  Then buy Koni, Bilstein, or other quality adjustable shocks and run them at the lowest adjustment setting.  Koni is very straightforward about this: the adjustment feature is there to tighten up the shocks as they become loose with wear, not to stiffen up the suspension.  On today's crumbling infrastructure your best handling will come from stock springs and high-performance anti-roll bars in combination.
    I'll tell you a little story on how I discovered this principle.  I had a hand-me down '64 Ford Falcon sedan.  It was a former telephone company service vehicle and was equipped with nothing that it didn't need to get from A to B.  My previous car had been a sports car, and I had studied suspension design a little.  I put an ADDCO anti-roll bar on each end of the car (it had none, imagine how that handled).  Even though it was equipped with Ford's smallest engine and a two-speed transmission, I was then able to keep pace with the 240Z that I frequently ran into on the rural highway we both used to get into town.  In fact, when I was feeling brave, I could pull away from him in the twisty bits.  Recently I bought a stiffer rear anti-roll bar for my Explorer, which understeered terribly.  It made a huge difference.  Stock springs, high-performance anti-roll bars, that's the way to go on the street.