Some of my favorites include the Cambrooke raviloi, any of the Aproten pasta (you can order this on Cambrooke's website as well), the Cambrooke pizzas, the Cambrooke meatballs, and the shaker cheese which I use it to make macaroni and cheese. I also love the rice that is available at MySpecialDiet and the Nutricia Apple bars. Trial and error with this kind of food is frustrating sometimes, but once you find something delicious it will be worth it (and believe me there are delicious options out there).
Just a suggestion- Make sure you try lots of different low protein foods and find out what works best for your son while he is still young and developing his taste for things. I am 21 years old now, and when I was growing up almost NONE of these low protein options existed. I got used to the tastes of real bread, real chocolate, real cereal, even real ice cream, which probably explains why I dislike the low protein versions those things. If I grew up with those things and never tried the real thing, I would probably find them delicious because I would have no comparison. Food and formula have come such a long way, even in just 5 or 10 years. Just a year ago, I was drinking a formula I could barely stand, but now I'm on the Camino Pro system (available at Cambrooke), which is a combination of convenience and taste my parents could not even imagine for me when I was a child! Just have an opened mind and remember that there are tons of possibilities out there. Best of luck to you! PS- Cambrooke wins my vote for best low pro food on the internet!