you could get a bar table. most of those are about 7' long. According to the previous posters website, they recommend 5' on all sides. What I would do is marki out a 7' table w/ masking tape and then get a cue or something that you could manipulate to the different size cues and see how that feels.
I just had a pool table installed and 60" is the bare minimum distance on all sides in order to use a full length stick. One small portion of my table doesn't have a full 60" clearance so I just bought a shorty stick for those situations.
I had a friend try and put a bar table in a similarly sized room... 3 or 4 cue sized holes in the sheetrock later he decided it was a bad idea... particularly if kids will be playing on it or semi-intoxicated or inexperienced people.. if its just you and your buddies or something it could probably be done reasonably well.. 13-6 is a good sized room
Nothing is more frustrating when playing pool then having to wory about hitting the walls as this will realy mess up your stroke. Even with a 7' bar table you will only have around 3' front and back to work with. I have a room almost 17' to a corner and I am still worried about having ample room when playing when I get an 8' table.