I would expect the right dedicated 2 channel amp to help with the Gallos. Different pre-amps will certainly be a factor as well
As described, your room and configuration might limit imaging depth but not width. Distance to rear wall may not be as big an issue with the Gallos as a result of use of side facing drivers.
LEss than optimal soundstage depth is not unusual and many live quite fine without it. THings can still sound quite good if things are tuned in well. The glass to the rear will likely have an effect. Try some different things possible within the room limitations and see.
As described, your room and configuration might limit imaging depth but not width. Distance to rear wall may not be as big an issue with the Gallos as a result of use of side facing drivers.
LEss than optimal soundstage depth is not unusual and many live quite fine without it. THings can still sound quite good if things are tuned in well. The glass to the rear will likely have an effect. Try some different things possible within the room limitations and see.