That is the real problem. Plants grown from the seed of hybrids do not necessarily come true to the parent plant - there are way too many grandparents involved. (Its why your kids don't look like you).
But citrus are weird and don't follow all of the rules. They produce two types of seeds: polyembryonic and monoembryonic. If your seeds are polyembryonic, they will be true to their parent. If monoembryonic, they will resemble the grandparent plants. The problem is that the only way to tell right this minute is to dissect your seeds.
Plant them NOW. The longer you wait, the less chance they will germinate.
After they germinate, the more vigorous trees have the best chance of being the desired tree.
PS to Carol: Prune! I had an avocado that I kept pruned to its space and still had way too much guacamole.