Fireplace Xtrordinair (FPX) has a lower BTU/no blower model called the "Custom Builder 35" that does not require a hearth. If you want a higher-BTU model w/ blower, I believe the FPX 36 DV-XL (36-inch Direct Vent-Extra Large) doesn't require a hearth if it's raised three or more inches (same for the 44-inch model). Here's a link to the FPX brochure in .pdf format. There's a chart near the end (brochure pages 18 & 19) that lists the specs & clearances for the various models. Here is a link that might be useful: FPX gas fireplaces

Well, here I am, coming up on month 14 of a 7 month project. Still don't have all my FPs bought, still not sure which I'll use in the MB and [possibly] basement family room. But I've bought mendottas for the living and dining rooms: Most other models allow you to 'turn down' the flame by opening a vent to outdoors, while the mendottas let you turn off the upper burners and dial back the lowest one. I came accross two issues that I learned couldn't live with: Uberclean brick surrounds and log sets that sit in a little pan atop the floor of the fp [leaving the floor utterly prisine]. Either shout 'FAUX!' so loud that I can't enjoy the actual fire. I'm surprised by how much I like Napolean's units with built in lighting: since a gas flame doesn't throw as much light as a wood one, adding the yellow-y electric light makes the fire seem much more cozy and authentic. But I'm all the more aware that we aren't all looking for the same things: an issue that disqualifies a unit for me could be someone else's favorite feature...

First of all, there is a 30% tax credit (on parts and labor!) on better-quality inserts right now if you can get them in service (not just paid for) by Dec. 31. I suggest you see if you can get an insert job done; Maybe Uncle Sam will pay for the insert if you cover the labor. Now for your main question about doing it without an insert. I looked into this once and concluded that without an insert, gas log conversions from any type wood burning fireplace are mainly for ambience, not heat. The best I could come up with was, I learned that some RH Petersen logs with GF in the part number are designed to work with doors closed and thus keep the heat in the firebox instead of going up the flue. Maybe we could hear from someone with GF logs. There are also some other brands that advertise "reduced vent" logs, you might ask about those. In both cases I have my doubts about, even if it does produce heat, how much, and is it practical to get it to work with a thermostat.

Years ago, with a real wood-burning fireplace, I got sick of the blackened, sooty area in the middle of the firebox (which was real brick). So I bought a can of firesafe spray paint and painted the entire interior black. My husband thought I was crazy, but it looked SO much better. So my point is that you should make your decision on other aspects... heat output, how the flames look, etc. If you end up with brick and then think it looks funny, it will take you less than $20 and 20 minutes to spray paint the interior. Just be sure to get the high-temperature paint.