Congrats on the kitties! I adore them.
7 weeks is a great time to take them home, especially since you are getting them as a pair.
You can also discuss spaying and neutering with your vet when you bring them home. We routinely perform these procedures on kitties as young as 6 weeks, and research shows no benefit to waiting and no detriment to doing it that early.
Congrats!! and good luck
