True, but in general, spring rates found in Japanese coilover kits are much stiffer than those found in springs and shocks kits.
But quoting a whole range of springs is pretty redundant, unless they came as options with the off-the-shelf kits we are discussing... As we all know I could go get a set of 20lbs springs for my coilovers or 500lb springs for my non-coilovers...
Also you can get drag pro coilovers with softer springs too, so it all depends on what you want.