hang in there- i think this might be a bit of a long one...
don't discount an older pup. my chihuahua Dexter's 2nd hand- and he is the best boy in the world- he's my star whale!
this lady i used to know used to breed dogs- a lot. so she was well known for having loads of dogs, so, sometimes if the nearby shelter was full or closed she would find dogs tied to her gate, but people knew they could leave a dog with her and she wouldn't ask questions. (she started off a fairly good hobby breeder, but got a little overwhelmed over time and became a little too commercial for my liking.) anyway, dexter was one of them; the lady had left him with her OH when she went and came back to find him in a sorry state so she left him at the breeders to be re-homed. knowing i had always wanted a chihuahua, the breeder (once she got him to a good weight etc) gave me a call and asked if i wanted him and i said of course, but missys litter were just 8 weeks at this point, so i'd have to see how he behaved etc.
when i brought him home and introduced him he rolled onto his back for the 6 pups to climb over him!
he's had a tough time of it apparently- and when we took him he needed over £300 in dental work done from a bad diet and lack of care- he was only 2-3yrs old! (since he was a private re-home i paid, but if you adopt through rescue things like that will already be taken care of). but as soon as you take a seat while he's near he'll be up like a shot to get on your knee for a cuddle... he's always closeby if you need him and if you're sad he cuddles in close to you.
when i moved out on my own (2 years after getting Dexter) the plan was that my 2 girls and Dexx came with, but my dad actually cried at the thought of Dexter leaving, and Dexx licked him in the face to stop him, so my Dex stayed with dad
but in the words of Amy Pond...
http://i1058.photobucket.com/albums/...ps6bec1e03.jpg
(had hoped the pic would have shown!)