Thanks for weighing in, everyone.
Looks like I need to try Cone 6.
I'm a little confused regarding the cooling though. One person suggested I cool faster, while others are suggesting ways to cool slower (with the fiber blanket).
It always depends on the glaze. The person who suggested cooling faster is probably right if you're trying to get glossy clear. For some glazes, especially mattes, slow cooling is better. For some, super slow cooling is best. Some potters use incredibly complicated holds and ramp downs for cooling saturated iron glazes. The only way to find out what works best is by testing.