HAHA!
I love your "I know nothink!" mentality Jake,
You're Big in the surpa community, You're Loved!
If you get $300 coilover springs, and then get decent struts to go with it, you're looking at $700 plus shipping, and then your stuck with factory pillowball mounts, which suck.
Supras are heavy, if you get a wussy spring rate, you will bottom out your strut and eventually ruin it. Super spring rates make for a shakey ride, but can be "tuned" out with an adjustable damper.
If you got the D2 units, you get this
"* 36-way adjustable dampening
* Made from high quality 6061 Aluminum with T6 for increased hardness
* Compression/Rebound adjustable
* Adjustable spring perch for height adjustment
* Adjustable body allowing maximum suspension travel
* Pillow Ball Top Mount w/ adjustable camber (not available for some models)
* Monotube High Pressure Design
* Electroplated body for protection from corrosion and rust"
That sounds alot better than cheap unknown spring rates that could destroy expensive tokiko or koni struts that aren't rebuildable.