Congratulations on the new bundles o' joy. Getting two bells of the same weight is a great idea. I am getting four this weekend. I am getting two 35 pounders and two 53 pounders. A RKC team leader recommended this assortment to me.
I really cannot see myself ever needing any more. I can swing from 35# all the way up to 106# now. Two handed clean and press and two handed snatch are terrific exercises. My 35# bells will be the classic style and my 53# bells will be the "Russian Red" style. The red style has paint over the top that makes the grip bigger and slicker. It is supposed to be harder on your grip and on your calluses. I am looking foreword to getting chimpanzee strong with chimpanzee strong hands to boot.
Up to this point I have been using home made bells from 28# up to 58# with a 1.5" diameter handle. I have been happy so far, but it's time to move up to the big leagues.