When you say dwarf fruit tree seeds, I'm not really sure what you have in mind. Almost all dwarf fruit trees are dwarf because they are grafted onto dwarf rootstock. The scion (top part of the tree) is genetically full-size. Another aspect to consider is that most fruit trees don't come true from seed. So, if you plant an apple seed from your favorite type of apple, the fruit from your new tree may not even be edible and is very unlikely to be as good as the original apple. Of course, there is some remote chance it could be even better.

If you want small fruit trees, purchase trees grafted onto a good dwarfing rootstock. Otherwise, try something like a couple of blueberry bushes or some of the other bush type edible-fruiting plants.