Bob's Red Mill says the ingredients in their 5 Grain Cereal are "rolled whole wheat, rye, oats, flaxseed, barley, and triticale." Ingredients are typically listed in order of quantity by weight (ie whatever a recipe has most of by weight will be listed first), if that helps. The nice thing is that if you mix up a batch, you can adjust it here and there until it is to your taste - its pretty flexible. Just be sure that you write down everything you do so that you can duplicate it!
You could also try the Hillbilly Housewife recipe for 5-grain cereal, although it's different from the Bob's Red Mill -
http://www.hillbillyhousewife.com/5graincereal.htm
My health food store carries 5 and 7 grain cereals pre-mixed in the bulk bins. This could also be an option, if you've got a good selection of bulk bins around.