Or mix them like me.

Fronts - h&r struts with eibach springs

Rears - h&r struts with h&r springs

I know it seems like an odd combo but overall the car sits, rides, and handles pretty good with this setup.

 

Just looked again at the website and:

Ride Quality:
CM springs enhance suspension performance while maintaining a reasonable level of comfort.
Engineered using rates higher than stock, often involving variable rates.
Created with ingenuity by the respected design team, CM's exceptional springs offer an outstanding driving experience that will never decline. Absolutely no sag, guaranteed.
Construction:
Highest quality spring steel is coiled using state-of-the-art equipment.
Stress-relieved in a continuous oven, shot peened and 100% set-removed.
Powder coated a rich, glossy burgundy to ensure long life and good looks.
High-tech equipment is used to consistently test the pre-production and production runs of every spring application built. Testing includes inspection for load height as well as rate.
Brand & color Variation:
ST truck springs are shipped to US addresses instead of CM truck springs (due to warehouse stock placement. Only affects truck springs). ST truck springs are comparable to CM truck springs, and are powder coated glossy gun-metal grey instead of burgundy.

Springs are made by these guys
http://www.rmwindustries.com/index.html
then sent out to the companies who they supply and the company powdercoats them the color they desire.
And just for a bit more assurance that the springs have great reviews and also a bit of a reason they could be purchased at such a low cost.
http://www.vcmc.ca/forum/showthread.php?t=1441

 

Now that is the research you should have done in the first place.