Does anyone know of any tropical-looking plants are hardy to 14 degrees Fahrenheit -10 Celsius?

Canna lillies (the top frosts of and they regrow again in spring), Washingtonia palms (some companies specialise in cold climate palms), They are not tropical but look the part - acanthus mollis. You don't mention which country you are in but check the BBC Gardening site in England, you may find some helpful information there. There won't be hundreds of varieties available but with some homework you find will some plants that are suitable.