Hi Nicole, and welcome!
When I got my first Savannah we got a beagle puppy at around the same time... it ended up that we got the beagle about a month before my F2 boy arrived. I do think not getting at exactly the same time is best, even though there aren't the disease issues to worry about it really is best to concentrate on settling in one at a time and forming your bond with them directly.
In terms of how an F2 or F3 will be with your family and friends, it will of course depend on that individual's personality. Just like us humans, some of us are more social and outgoing than others. How they are raised by the breeder will affect this and then how YOU socialize the kitten when you get it. Some people get caught up with their kitten and so don't have anyone over to their place for months and then when they do the older kitten/young cat is freaked out by that change. Just like socializing a puppy, you want to kinda start as you mean to go on... if you want them to be comfortable with family and friends you need to make an effort to have them over to your place a lot when the kitten is new-ish (after an initial quarantine and bonding period). Make those interactions positive ones...so not allowing them to all grab the kitten for cuddles the kitten does not want, but treats and toys and FUN.
Rafiki gave you good information. yes, the largest SVs seem to be F2 generation but some of those F2 males are relatively normal sized. My first F2 was never more than 13lbs in his life. His younger half-brother (same mom) was over 30lbs but the littermate sister to that giant was only 9lbs. I was just messaging the other night with a new SV owner that was so disappointed that her Savannah was not as large as she had expected... she loves the cat's personality so it made me sad that size was an expectation ruining her experience a little. Better to expect a cat proportionally taller than the average cat but not necessarily LARGE...then you might be surprised by more but you won't find yourself disappointed in that relatively unimportant trait...
As to male vs female... males I find are more laidback but also almost more needy of your attention/affection. While the females quietly demand your fealty.... and get it. Despite having some great male Savannahs, it has been some of the females that burrowed deeper into my heart.
As to introducing children, I believe that if you do this thoughtfully it works out. I struggled with infertility for 14 years and so my kitty population was well-established here before I brought home my baby two years ago. I had six cats, of which two were F1s. I somewhat approached it like I would introducing most other animals.... I thought about changes and how it affected them. We accumulated baby stuff slowly and put it around the house. The cats thought the bouncer, cot and swing etc were all great new kitty furniture. When I was in the hospital my husband came home twice a day to feed and play with the cats but also to take a baby blanket that had swaddled our child and he laid them out on our bed (where the cats always sleep). They happily slept on those blankets and we felt that helped them get to know baby's scent. When we brought Lola home we treated it as calmly as possible, let them sniff and reassured them with lots of love. It's hard as a newborn human baby is exhausting, but we consciously made time for the cats for cuddles and playtime. There were issues, one of my cats tried to pick her up like she would a kitten once, and one of them to this day dislikes my child. That can happen when you introduce another cat, so we just manage the situation. On the whole, it went really smoothly but I believe it was because we recognized how huge a change it was to our cats and made effort to help them with that change.So many pet owners don't, they bring home baby and suddenly have not time for their pets who were used to being their owner's whole world and "just like one of their children".