Hi! The columns in the current background looks more Greek to me. Cmiiw but seeing from several pictures I think columns in Greece/Rome and in Palmyra are of different styles - maybe materials as well? I'll try to illustrate my point:
or.. how about using the Lion of Al-Lat statue as base for the background? Obviously there are modern elements here that should be scrapped off..
Anyway, it's really touching to learn that the community are planning to create together a tribute to the lost Palmyrene civilization... :') I hope this is the last civilization whose remains intentionally destructed by those barbarians.