There's no way of knowing what quality fruit you'll get if you plant seeds, and it'll take years to find out. If you want to get the fruit that tree bears, the only way to guarantee that is by propagating that tree.
It's not that hard to propagate many fruit trees from cuttings. Cherry trees seem to do best with branch tip cuttings. If you want to get some of THOSE cherries, you should take a bunch of cuttings from the tips of the branches, put them in some pots of potting soil, and mist them several times a day under a small plastic tent(out of direct sunlight).
You might check the original tree to make sure it doesn't have a graft junction near the ground. If it does that variety of cherry might not be hardy enough for your area, and you'll have to graft it onto a hardier rootstock.