If you like where you are & the only reason you are considering moving is for the cat(s)....consider the vertical possibility, kitty shelves can look pretty awesome, serve to increase kitty entertainment, & if you are "handi" you can create some of your own tunnels, landing spots, caves, sunning areas, etc... there are multiple posts in here on this & some are very unique.
Again there are multiple posts as to why quarantine is best, please don't assume if the kitten is healthy he doesn't need the quarantine period, he needs to learn to come to you & bond to you just like you need to learn if your kitten likes to be touched on the head or on the back, or like Eddie EVERYWHERE.... trust is developed here. Eddies quarantine was LONG...due to Mojo skipping his; so whereas Eddie is very secure with us, Mojo

is only truly happy with my husbands attention...merely tolerating the rest of us.
If it doesn't work then I'd look to give him back to breeder and lose $2k.
This I get stuck on... you have alot of decisions to make, maybe a few changes coming up that will affect your present kitten before you get a new one. I can see your devotion to the first cat...but is the second kitten optional to you? Don't answer that until you go read about Bucky... & of course there are others....but this is every breeds tough nuts. To some breeders your answer wouldn't matter, to others it definitely will.
Getting a Savannah of any generation is going to raise the energy level in your house

. Putting an SV with a "very laid back" baby is going to change her outlook, she will have to decide to dominate or not, but the SV is HIGH energy coming into your LOW energy atmosphere. Are you prepared for a cat that will knock down your pictures, rip up your favorite speakers, eat your mail, & snuggle in your pillows? He will at least try to take the food off your plate

...maybe even open the fridge for that left over chicken, the bathroom door for the toilet paper rolls, locked cupboard doors where you thought

the paper towels were safe...Eddie has just learned "Off" means to hit the light switch...we are onto our 4th set of "kiddie" locks...and he is an "angel" that keeps our tables spotless by sliding in @ moc 10 & sliding across them

.... finish your changes before adding an SV...making all transitions easierred heart.