I had a westie (West Highland White Terrier) and I can honestly say he was a wonderful dog!! They are much more obedient than yorkies. I think you are thinking about the Cairn Terriers which are similar but not white. The Cairns are quite active and can be destructive. That being said I didn't have mine as a puppy, so I can't speak about that. He was easy to train and I could even have him off lead (which isn't recommended as they are prey dogs) but he would stay right by us on walks.
I loved my Scruff McDuff!! He was wonderful. The grooming is a little much if you want to truly have a hard coat which is correct. They have to be stripped instead of cut (hairs plucked out). But they can be cut instead, they will just have a softer coat which is not so soil resistant. Also trying to keep them looking white was a little bit hard sometimes.
It is because I loved my westie so much that I became interested in yorkies. I chose yorkies this time because they look very similar to westies, but are smaller so you can bathe them in the sink instead of the tub. (Saves my back) And also they are not white, so dirt doesn't show as much.
If you get a westie be sure to ask if there are allergies in their lines as they are prone to allergies and if you can avoid them it's much easier.
Hope this helps.