Okay, you crazy cat person!
Two kittens will keep each other occupied! You will probably feel a little left out. First of all -- the coloring and markings of a bengal are simply a personal preference. All bengals are valued about the same -- depending on their F generation (removed from the asian leopard cat), coming from a long line of Supreme Grand Champion show cats, and the breeder's reputation. A bengal cat is a bengal cat.
I think if the breeder is socializing them together, they should be fine together. Like Brian said ... just watch and see how they interact. They are kittens, so they will rough and tumble a lot and I think having them together in the safe room will help them transition to your household.
I noticed in the other thread you started talking about "cats" and I was thinking, no, they are only getting one cat. What is going on? Now I know! Bless you for opening up your heart and home to two little ones! One is an adventure, two ... well, I don't know what two might be. Happily, you are about to find out!!! Can't wait to hear back from you once you bring them home on Saturday.