Rice Chex, corn Chex, Kix. There are some yummy rice/soy crisp snacks (like rice cakes but smaller). If you make your own bread you could just use some alternative flours (amaranth, quinoa, garbanzo bean, rice, gluten-free mix, etc.). And you could make your own crackers with those as well. I saw a lot of other good suggestions here for fruit snacks & stuff, too.
As for the allergy info... we were kind of blindsided by my DS1's allergies, as my DH and I don't really have any. Maybe occasional mild hayfever some years. So I was pretty casual about things like peanut butter, eggs, etc. since I figured the chance of allergy was very small. Now that I know better, I wish I'd known better then. ;) Honestly, I think you're being wise in being cautious about it. If you, your DH, your parents/grandparents or his parents/grandparents have ANY food or environmental allergies, the chances are much higher that your kids will have some.
There is a lot of disagreement even among allergists as to whether or not avoidance of a food decreases the chance of allergy. Ours believes that it does, so I plan to keep the top 8 allergens (tree nuts, peanuts, fish, shellfish, soy, egg, dairy, wheat) away from my younger son for quite a while yet. Just in case. 'Cause people think it won't happen to them (I sure didn't) and then you're stuck in the allergy lifestyle. And believe me, it's much more of a hassle than finding alternatives for wheat for your baby's first two years.
So good for you for being cautious. I hope that it pays off & your son will be allergy-free! :)