Here is a gorgeous fireplace for your modern space. The Superior Fireplaces DRL2000 Linear DV Fireplace is available in 35, 45, and 55-inch models. It comes with electronic ignition with battery backup. This particular version has an output of 13000-18000 BTU.
This fireplace has a tempered glass and protective screen. You can use optional driftwood logs and river rocks for a more classy look.