We have one, but don't use it as much as I'd like. I bought mine to use for shopping and whatnot but have found it gathers more attention then what I would like. Everyone has to stop you to look inside and comment...it's not discreet at all.
But it's great for long walks that your Yorkie wouldn't be able to keep up on.
I bought mine from a website I heard about here on YT but cant remember. If you search "strollers" I'm sure you'll find tons of great suggestions.