Speakers for small listening room

I need some help/advice for getting the 'right' sound for my system that I have in my small listening room.
The available space is only 11ft wide by 18ft long, and I currently have Kef RDM3's with a Marantz PM17-A integrated amp. I listen to mostly classical and jazz with some pop/rock.
My problem is that given the width of the room I dont seem to be able to get a good soundstage or decent imaging compared to the same set up in a larger room (our main living room where my wife refuses to have the Kefs set up).
Given the size of the room, would I have better luck with a smaller high quality monitor speaker? I am willing to pay around 3k to get something that does more for me than the current set up, and would also consider changing amplification if necessary.
Worst case... is there something about this size room that will prevent me from getting the kind of soundstage that seeems to come with a larger room.
I am kind of new to this and no acoustic engineer, so bear with me if these questions are naive or stupid!!!