I own the montille in a room very similiar in size to yours. Depending on the volumes you listen at, you may want to look into the devore line, either the super 8's or nines are in that price range. While not that effecient, they are an easy load and a great match with shindo.
My gibbon 8's are out being upgraded/repaired now, as my 19 month old used one of the drivers as a bongo. I am using an omega XRS in the interim. It's a great speaker for the money, but not up to the 3times more expensive devore. I haven't heard their top of the line speaker though (maxhemp).
Another interesting used option would be one of the phy based speakers on the market - musical offerings, tonian, ocellia
etc...
My gibbon 8's are out being upgraded/repaired now, as my 19 month old used one of the drivers as a bongo. I am using an omega XRS in the interim. It's a great speaker for the money, but not up to the 3times more expensive devore. I haven't heard their top of the line speaker though (maxhemp).
Another interesting used option would be one of the phy based speakers on the market - musical offerings, tonian, ocellia
etc...