I just tried pricing a reservation for a virtual family identical to yours, Morgan, and I, too, had trouble.  I can tell you that because your youngest child is under the age of three, your family can be accommodated in any resort in which standard rooms sleep four (in other words, pretty much anywhere).  Your youngest can either sleep in the portable crib or with you and your husband if that's how you're comfortable.  The updated website has been a bit wonky; you might be better off calling 407-WDW-STAY until they get all the kinks worked out.  Good luck!