Lee- the Tanabe springs are a great option for your NSX, as they are very close to the Type-S spring rates. However, if you use them on OEM shocks they will blow out quickly. The stock shocks are not valved for such stiff springs. If you are just interested in lowering I would recommend either getting Bilsteins and using your OEM springs on the lower perch (drop = 7/8") or going with a dedicated lowering spring that is close to stock rates like Eibach, Dali or Comptech. You might also check my Comptech Sport kit for sale
here. It would provide the lowered look you are looking for.