Sounds like a fun pack! I don't know where your other dogs are from, but be sure to do lots of research if you are buying from breeders. Avoid pet stores at all costs. My Chihuahua, and many others here, are rescues, and they can be quite common in some areas of the country. Doodles are the current "it" dogs, so there are many people breeding them who are clueless or just plain greedy. Not that that doesn't apply to some Chihuahua breeders, but it is probably worse in doodles currently.
First time Chihuahua owner with many years of dog experience!