By one year old, chances are your male will have soaked your household. Especially if there will be an intact female cat for him to wish to impress...and she may well join in the pee fest. Neutering/spaying after they start spraying can be risky for actually stopping the behavior. This is a risk you will run. That's just cat hormones. There's a reason we spay/neuter our pets, it makes them better pets and more pleasant to live with.
The miracle of birth for your children could also turn into the reality of birth when something goes wrong... when we want our children to see the joy of new life, I'm not sure we alternatively wish them to experience the sadness of early death, nor the possibility of deformities etc. It's truly nature, and it doesn't always run smoothly. As a biology teacher, I am guessing you know that.
In terms of wishing to know the genetic possibilities of the offspring, you can send off cheek swabs from your two cats and know what genes they carry for color at least. We don't have a DNA test for classic pattern (marble) so that can still be a surprise, but you could find out if your black girl carries for colorpoint (the snow gene) and whether your snow lynx boy carries for nonagouti (solid)... to be able to see what combinations you may see.
You questioned the fate of the Savannahs used in programs? Mostly, good breeders spay/neuter their breeding cats at a relatively early age (I like to spay my girls after 3 litters and before they are 5 years old) and place for a minimal fee (generally the cost of spay/neuter) in a pet home where they can live the majority of their life as a treasured pet. Many ask why the breeder doesn't keep them, and really it if for the benefit of the cat...not to live in a very large pet household as that doesn't suit a lot of cats, they often much prefer the attention of being in a smaller pet household. When the breeder doesn't step up, there is rescue. Savannah Rescue takes any Savannah in need and finds it a great new home. We have over 11,000 people on our waiting list and I think I added up 26 Savannahs incoming last year...they are highly sought after. Not many rescues have such a disparity... it means we can really find fabulous homes for our cats. We have not found that F1/F2s don't do well inside the home. In fact, last year we got an F2 that had been living as a feral cat for a long time (as far as we could tell from his condition)... we thought he might have a long transition to living inside a home, and made arrangements with his new home to have an attached enclosure. Within a week he was spending most his time indoors and WITH his new human...there's a lot of myths and misinformation about how "wild" this breed is and how they cannot be good pets, the facts add up to a very different story.