Actually, if you'd like to preserve the open-hearth you have now, gas logs like the Grand Canyon ones you have pictured are pretty nice. I also like the logs by Golden Blount. Both Grand Canyon and Golden Blount use hyper-realistic logs. You can get a very convenient remote-controlled valve in either case.

Unfortunately, the installation of vented gas logs will require having the damper clamped open inmost jurisdictions, which will affect your heat conservation.

If you would like something more heat efficient, I'd suggest an insert by Mendota or FireplaceX. Either will provide good heat efficiency and realism.

This is a FireplaceX insert:

If you have a masonry fireplace, you might be able to install an unvented gas log and leave your damper closed, thus preventing heat loss. It won't offer as much heat as an insert or as much realism as a vented log, and there are other concerns to address (mantels clearances, local codes, etc.), but it might be more affordable and get most of what you are looking for.

Consult a local hearth professional to find out your options. Find one here:

National Fireplace Institute Certified Professionals

Hey Tom, thanks very much for the gas fireplace info. Exactly what I'm trying to balance, but lean towards realism even at the expense of some heat loss. Even with damper open for a vented model, I'd think the heat loss is minimal since there's a glass cover over the FP opening. I just tonight found your response so I'll check out your website and photos, etc., and get back to you. Thanks again.

@Jas, some folks find the most realistic option to be gas logs in a wood burning fireplace, where there are no glass doors. However, efficiency is effectively zero, and it is hard to get an open hearth unit to draw properly in a modern, tight home.

FYI, typically, you cannot operate a unit that has a damper with the glass doors closed. The doors are simply for when the unit is not in use. Tempered glass fireplace doors have a tendency to explode if used improperly.

Tom, I measured the FP opening and see that it's not as wide as I thought. It's actually 35" wide x 29" high. I just started following your links to Mendota and others. Anxious to check out Grand Canyon and Golden Blount. The house has been expanded to a small jewel, about 1700 sq'. The original house and its masonry FP were both built by a freed slave in 1847, so the house carries his name (Solomon Fry) on the National Registry of Historic Places. It's in the historic district of a town called East Greenwich, Rhode Island.

Besides inserting a vented gas system into the original FP, I also want to add another gas FP in the new master bedroom which was added about 6 years ago. I'd like that FP to be somewhat different from the LR unit. Yes, the national registry allows me to change details like this in the house so long as I don't change the exterior or windows, etc, or change the character of the house itself. The LR fireplace appears to be a standard masonry brick with mantel, so it should work for gas products. Any suggestions you can offer are greatly appreciated. Where is your business located? I will search the site later tonight. Again, thanks very much.