There are a great many tomatoes with few seeds.
Basically most of the heart shaped ones and the Roma types have less.
Many of the early parthenocarpic ones have very few seeds in the first fruits and less than normal in the later ones..
Specific varieties of many types are
Chapman.
Red Penna
Red Bulgarian
Heidi
Opalka..really good one
Mama Leone
Ashleigh..very low
Regarding the Burpees Sweet Seedless, I know this tomato and can categorically say that Burpees are kidding you.It is not seedless, the seeds are there, they are smaller,kind of immature but they are there there nevertheless and there are plenty, their claim that it is a great tasting tom are exaggerated too I found it exactly the opposite.I would not grow it again.
If the reason for the need for seedless is diverticulitis that one would not work for you at all.
You would be better to go for something that has exceptionall large seeds so they are easier to pick out.
There are a great many more varieties than I have mentioned above so plenty of low seed ones out there with only about 10% of the regular amount of seeds.
XX Jeannine