room dimention question

As far as electrical goes I'd put in dedicated circuit breaker and wire just for your audio. I'd use the heavier gauge that is for 20 amp circuits and use a hospital or other specialty AC receptacle.

Some advise far more easily provided than adhered to:
1) 2 -3 dedicated outlets, isolate digital from analog,
2) 1" sound panel on primary reflection point on ceiling and and 2" on walls adjacent to speakers, also on rear wall behind speakers. Also absorbers or reflectors behind listening position. Check out ATS Acoustics web site (atsacoustics.com) Piper City Illinois 866-787-7881 for panels and DIY material. I built my own and saved $$$.
3) Some form of bass traps in corners behind speakers. Also can be DIY.
3) make room rectangular, with long wall 1.3 to 1.4 times short one. Consider taking a long wall/near field approach to speaker placement and listening position.
4) if dealing with concrete floor, know this can be an issue. Can sound cold. I have this issue and am considering framing in a floor. I have 8'9" ceiling so could spare the 4" space. Right now I am using Wall to Wall carpet over thick pad and an additional area rug.
Place your equipment along side wall not at point of primary reflection as opposed to between speakers. Better sound stage and image.

Having a dedicated room makes for a great audio experience, regardless of the constraints one has to work with. Enjoy and good luck.

Catfishbob,
what are the other dimensions of your room? That might help answering your original question. Thanks.

Catfishbob,

Sit in a lower chair.

But seriously, you can treat the ceiling just like you would treat the side walls in a problematic room by use of absorption panels or diffusors. While these treatments are not as good as having the perfect room dimensions, how many of us have that?

7'-3" is not bad my room has only 6'-6". One trick I used to gain some height and reduce reflections of the ceiling was to leave the joists exposed and to install one layer of rock wool covered by a fibreglass ceiling tile. See pics of my system "small room big sound".

This has really helped with the room accoustics in my small space.

As for the electrics, definitely run a dedicated line to your system at least 15amps. I recommend cooper medical grade outlets at 30$ a piece. The ones with green dots.

Also I agree with Mesch recommendations.

Enjoy, designing a room from scratch is loads of fun!