There are no such thing as drift coilovers, it's just part of marketing.
The 10/8 spring rate for the streets isn't harsh at all. I have Tein SD's and I daily on them.
Once you setup your your preload and damening, you shouldn't have and problem with qrip.
The setup doesn't just come from the coilovers, but the biggest diffrence on your car will be the alignment setup and tires.
As for your canyon running, it all depends on the roads in your area.
Most of the time they tend to be bumpy so you should soften the dampening on your car and depending how low your car is you might need to raise it.
After you finish dealing with that, you can never have too much practice and skill.
__________________
|