A.L.
I would agree that your son might not be ready yet. I wouldn't stop trying though. Our son was born 10 weeks premature, so we had a big issue with his gag reflex. Many times something would hit him wrong and everything he ate for the last three hours would come up. SOOO fun. Just be careful and watch your son. You'll get to know his "signs" early and hopefully prevent the throw up.
Here are a couple suggestions that the specialists gave us. Take something he likes, like the puffs and grind them into a fine powder. Then scoop some baby food (without lumps -like applesauce) and put a pinch of the puff poweder on top. Then cover the powder completely with more of the baby food. Your son won't be able to feel the ground up baby puffs but his mouth can still get used to the texture combination. We only had to do this for a few days before our son was okay with some textures. (it also works good with crackers, graham crackers, etc)
PS- our son still doesn't like the textures of some things and can gag on a dime ;) He is two now. All kids are different.. Good luck!
A. in SLC UT