The Heresy will play *loud* with a 50W amp and are very well-built speakers. I think they sound best when elevated 3-6 in. and tilted back a bit.
The Gallo Ref 3s could also work in that space and I'm somewhat biased towards them, I own a pair. They are *fantastic* speakers and not super-fussy about placement.
They do sound best if you can get away from the back wall 2-3 ft. and at least 2ft. from the side walls. They will not play as loud as the Heresy (the Heresys excel at rock music), but their soundstage and imaging is sublime. In addition, their rendition of vocals is second to none, an excellent jazz and vocal speaker.
Another option for your space would be a sub/sat combination. This might give you more placement options and would certainly deliver a full-range sound. I am biased towards the "British" sound: Spendor, Rogers, etc. They excel at vocals but are usually somewhat lacking in the last octave. That's where the sub kicks in and rounds things out.
In addition, the Gallo Dues could fit the bill and sound just terrific with a properly matched sub. There are a pair on Agon for $750 right now. Add a $500-700 sub and you'd have a killer system for your room and tastes.
So many choices...[smile]
-RW-