I've done the usual chicken ,tuna , or ham salad stuffed in a tomato. My grandmother had a strain of tomatos called tomangos. They were tomato tasting and texture but shaped like a pepper. They were really good stuffed.
There actually still are varieties of both red & yellow tomatoes grown & meant specifically for stuffing. Like you said, they're shaped rather like bell peppers & are virtually hollow inside. Here's a link to a seed site with a good pic of one of the yellow types: