Definitely put 22-55 over K6s in most cases. After playing a bit, it should be a lot easier to assign ranges depending on play, especially if they are a regular who you know would open 22-55 over K6s).

You can also try BigBet Software . It's a program similar to PokerStove but allows you set hand rankings by different types. One type is "6max cash groups" which gives a much better range for what you are trying to do.