In general:
If there is someone in the area that makes them, a custom insert can be built to match the fireplace. If it were to be the main source of heat, get one with a fan. No modifications required especially if there is a blower system already around the fireplace (heatalator(sp?)). It can be rewired to power the stove blower.

If the fireplace draws well, effective isn't the word for a good one. A good load of wood before bed will give you coals in the morning. I don't remember if we stoked it in the morning or after I got in from school. You just have to close the lower vents and almost close the sliding damper that should be built into the top of the insert. Not closing the vents/damper will have you sitting on the porch with the front door open (once it is lit, they burn HOT).

Specific to the question
What are the association rules regarding propane tanks? Is gas service readily available or do you already have gas?

Ventless gas logs have five primary advantages over wood: You don't have to deal with getting a wood pile built up for the season (and store it). No mess from hauling in a handcart of wood a day (this is if it were your main heat source like ours). No wood ashes to clean out (frequency depends on type of wood, size of fire, & design of fire place). The chimney can be sealed such that no heat is lost.

I've lived with all three (fireplace with heatalator(sp?), same fireplace w/ custom built insert, & gas logs) and a free standing stove. Even though I miss having the fireplace with the insert, It doesn't beat not having the associated mess or having to get wood in on a regular basis. Modifying the existing fireplace to run a stove may change the way it draws. The one I've had experience with drew poorly. I think it was because it had a long flat section between the stove & the wall. It can make the difference between lighting large split wood with newspaper & a few scraps of wood and getting frustrated & using a propane torch.