Listening room in Attic or Living room???

Before I spend 40-50 K on a high end system I want to make a space that will not present major problems from an acoustic matching point of view. I am still not decided on speakers (Vandy %A, Wilson WP & or Ariel 20T) The width of the living room is 13 feet 10 inches wide from base board to baseboard, about 35 feet long combining the dining room and living room and 9ft ceilings. This is new construction (thin sheetrock) but solid oak floor and a thick carpet (area rugs).

I could possibly put the speakers at the other end of the living room which is the entrance to the dining room, just in front of the two columns. This would minimize the open side wall on the other end but now how can I position the electronics to still allow an uncluttered walk through between the dining and living rooms. I suppose the CD and preamp could be to the side but how can the power amp or monoblocks be to the side? I know the speaker cables need to be the same length etc. I first thought about creating a shelf between the ceiling and the beam separating the two rooms but I don't know about heat buildup. The speaker cables would also need to be longer runs to come the 8 feet or so extra down to the floor level (just a crazy idea). I really don't want to partition off the two rooms (have to divorce wife).

As things stand, it is a long room. The speakers if positioned 7 feet apart would only be off the side walls by two feet. Is this enough? Please let me know what your thoughts are.

The second option is to finish the attic space (now no heat and a plywood floor) but opens to the second level of the house over the garage. I could build in acoustic treatment from the start but I don't know about the dimensions. The shape of the ceiling en face is trapazoidal. The ceiling height at the level of the horizontal rafters is 7 feet finished but this spans only 6 feet across. The beams then slope downward from there to one foot off the floor. The useable floor dimensions would be about 15 feet by 15 feet since the side walls slope downward from the 6 foot wide flat part of central ceiling. The actual plywood floor dimensions are 19 feet by 19 feet giving the room a big feel at the listening height. I don't know how such a relatively small cubic foot space would sound acoustically with the sloping side walls and reflections. With acoustic treatment perhaps this could be controlled. Any thoughts? I can email pictures of the space if it would help. Anyone have any dealings with RIVES Audio. Are they hype or really worth the investment?