Your check is in the mail! If we keep this up Susan may even believe we know what we are talking about!
You are right on regarding the acid/base stuff. One needs to only have 20-30% of cals come from veggies and fruit to get a net alkaline situation. That number can vary quite a bit depending upon how much fruit vs veggies one is consuming.
Now fats are typically neutral with regards to acid base balance but nuts and seeds can vary from quite acidic to moderately neutral. I think Loren Cordain has a good list of this stuff on his site.
So the Zone is great with regards to acid base balance (if you are sticking with fruits and veggies for the carbs).