I would suggest having some real artisan sourdough as part of your 20% - Udi's is great, if you have access to them. Wheat isn't that scary once it's been soaked and fermented, but unfortunately most commercial "sourdough" is barely a step above Wonderbread.
I also find that having another kind of starchy carb (quinoa, tapioca, potato, sweet potato, chickpeas, lentils) now and then pretty much eliminates my desire for bread and pasta. I know none of these foods are considered optimal by Primal guidelines, but if they can stop you from eating wheat, it's still a significant reduction in harm.
“The whole concept of a macronutrient, like that of a calorie, is determining our language game in such a way that the conversation is not making sense." - Dr. Kurt Harris