ok, i was going to suggest a Rat Terrier/terror, but though thay have short hair, they shed. and when they shed, the hair is impossible to get out of stuff.

a breed i will suggest from everything i've heard about it, though i never met one, and though they are long haired, is the Cavalier King Charles Spaniel

if you are to go w/ a chihuahua, i suggest those of the larger lines. (more stable temperment imo.)