Hey Harriet, We're having similar issues right now fitting a gas fireplace into our new place. It will look fab, but at 20" deep it'll eat up a fair bit of floor space.

Best bet for your space is a fireplace that runs on ethanol gel, since they don't need to be vented and don't take up much room. Have a look at InFlame as an option for something more trad looking, though they do have a couple of modern styles. Alternatively, check out Bergo in the Distillery District in Toronto; they carry a sleek stainless steel model called Chimo that's wall-mounted. And if they're both too large, then a tabletop version is available from Generate called Apollo, click here to take a look.

Cheers, Arren