Question about dogs: which would you choose?

Chihuahuas are very temperature sensitive. While I have never owned one, I have heard they can prove hard to potty train and train in general. With most toy breeds, they will probably also be pretty yappy. Are you familiar with dogs? I would suggest training whichever you choose to get (as most with toy dogs don't), because when your dog learns it can rule the house, it's not fun...and they can get pretty bratty. I have a toy dog currently though, and she has been doing very well. Your dog will definitely have lots of love, if there are no other pets. Sounds like you've thought it through well!