Is a small engine with a turbo a good idea?

Why not? Its mostly a question for ones self. If you are a big engine person that wants muscle and doesn't mind the massive fuel consumption then a small engine with a turbo is a bad idea. But if you don't like big engines that waste a lot of gas but hate the lack of power in a little 4 cylinder then by all means, a small engine with a turbo is a great idea.