Get one bro, you wont regret it!
My girlfreind has a Yorkie (female) and I absolutely adore her! She is not only energetic but also (despite popular belief regarding small dogs) highly intelligent and obedient.
You are dead on about a Yorkies attitude as well. Our dog (Macy) doesn't back down from anyone or anything. She's very protective of her own for what it's worth. She's only 5 lbs. full grown but
she fights like a rabid sewer rat!
I look forward to seeing her so much (both of them) that I find myself telling people at work about her and start showing them pictures of this little ankle-biter.