Well, multiple dog household chiming in here! GOOD MOVE on getting opposite sex dogs, for sure.
Can't say I've raised two puppies together, the established dogs have always been adults when I've brought a puppy in. I'd say with puppies you would have to make sure to have plenty of time with each one separately so they don't bond too close to each other instead of you & your wife.
Apart from increased veterinary/food expenses, the main problem I've had with multiple dogs is TIME - I often feel guily that I'm not spending enough time with every dog, but maybe that's just me...
Also remember that two dogs will often act naughtier than a dog alone if left to their own devices, so good for you in crating! Two young dogs can do some serious damage around the house...
Have fun with the puppers!