Good, better, “best”, consider a unit designed without the need for a circulation fan. Valor makes excellent, energy efficient natural gas fireplaces. Please call 1-800-468-2567 for more information on the excellent selection of Valor fireplaces and the location of a dealer near you.
Keep in mind that you want the best efficiency without a fan for both radiant and convection heat. Models designed with a fan tend to become far less effective when a power outage occurs and the fan is unable to do its job (when you need it most!)