Concats on you’re potential new furries. I believe two are as much fun as one and they can keep each other company. The breed doesn’t make a difference since you’re bring them home at the same time. Kittens aren’t usually weaned by mom until a minimum of 8 weeks.
Before you bring your kittens home, prepare a small room or space that will be theirs for the first few days or weeks. Having a smaller area to explore at first will help your kittens get comfortable with their new home. Be sure to secure all electrical and blind cords because kittens will get in trouble. Have all the supplies needed available and ready, such as water and food bowls, kitten food, a litterbox, a scratching post, safe toys, a bed and a breakaway collar with a bell. I say this about the bell because you’re not used to have kittens around so this will give you fair warning. I recommend having them micro chipped just in case they escape. Ask their vet to show you how to trim their claws.
Since you have a dog, is it possible to find two kittens that are familiar with dogs? It will be stressful if they’re meeting the new “other” if either haven’t see one. That’s not a requirement, just a thought on my part.
That’s about all.
Good luck
PG