HELP Streaming HD content to my Theatre Room

[Dwayne]

I have recently converted a garage that is NOT CONNECTED to my house into my home theatre. From the door on my house you take 3 steps outside and open the door and you are in the theatre. The house is Brick and the theatre is wood. My computer and modem is in the house not on the side of the home theatre. We are looking at if it was a straight shot to the theatre from my computer and modem approx. 125ft. My Blu ray players are ethernet and wi-fi ready. I know that a hard line of ethernet cable is the best way to do this but my attic will not allow this and moving the computer and modem is not an option. Running ethernet cable outside under the eaves of the house would be approx. 175ft. My question is do these routers really work and do they work well. My theatre is running off the same electrical circuit as the house and do these electrical outlet streaming devices really work and what would be the absolute best way to get a internet connection to the theatre without running alot of ethernet cable outside. I am not the most computer literate when it comes to home networking so I could really use some good advice from the people that appreciate and know HD Blu ray equipment. Both of the doors leading to one another have windows on them and there is a window on the same side of the house and theatre "if that helps". I expect the signal to be good and have no drop-outs so can this be done. HELP!!!!!!!!!