While cleaning out my garage, I stumbled upon a radiator cap from my son's Mazda B2600i truck. I thought it looked familiar and compaired it to my KDX cap. They are exactly the same except for the pressure rating. Check out a local auto parts dealer with the KDX cap in hand and start comparing.
BTW, the cap was labeled as .9, whereas the KDX was 1.1. I used it all day today and did notice it vented to the overflow easier. Keep in mind that a cap with a higher pressure rating might cause you to blow out one of the plastic plugs on the radiator when out on the trail. Be careful!
I use EVANS. It is great stuff. Non-aquious, you need to purge all water from your system. A wet/dry vac works great for this. Not only is it expensive, they charge $12 to ship a gallon of the stuff to your house.