The "real recipe" calls for pine nuts instead of sunflower seeds, but I think pine nuts are just too darned expensive, so I sub in the sunflower seeds. You could very well try it with walnuts, as well.
As far as the number of garlic cloves, again go by your taste, but the more your palate can take, the better, as far as health benefits go.
I put honey in my Pesto as it seems to cut the strong taste of the garlic, allowing me to add more cloves, and it does sweeten the flavor a bit.
I use my pesto with whole wheat pasta and veggies, spread it on a whole wheat tortilla when I make a veggie wrap, and I smear it on my Thomas Light Whole Wheat, or Multi-Grain English muffins. Sometimes I put some goat cheese on the English muffin as well (okay, sounds weird - but is pretty darn tasty!)