7.1 set up with all rears on the back wall

What's the point of having a 7.1 set-up with no rear-vs-side separation in the surround field? Sounds meant to come from your sides will come from behind you. Sounds meant to come from the back will also come from behind you. Better to stick with a good 5.1-speaker layout than shoe horn a poor 7.1 layout into your room.

I would not recommend trying to do the speaker layout in the first picture. Doing it that way would be a waste. You would be better off with just 5.1 or 3.1 instead. The second picture looks much better. You may have good results with that configuration. Not perfect but sometimes you just have to work with the room you've got and make the best of it.

With placement that close to your seating position I recommend you go with dipole surrounds.

+1 for the dipoles. I've got dipole/bipole speakers and I use them in dipole mode. They have dual tweeters and a single 5 1/4" driver in each cab. Sounds good. They are about 6' from me on either side and do a very good job of diffusing the sound.

And a +1 for ditching the 7 channel setup in a room like that. There simply isn't enough space along the back wall - no separation from the side and rear surround.

I recommend the layout in the first diagram, but with a 5.1 setup and ditch the rear surrounds.

I used bi-pole in-wall speakers ( Definitive Technology BPZ/A ) for my back surrounds and they work surprisingly well with the couch only 24" from the back wall. They have two 1" tweeters and two 6.5" mid-bass and are canted at 30 degrees. I have direct radiating for my side surrounds.

If you really want to go 7.1 you can. Bring your couch forward a few feet (at least 2) and separate the rear surrounds a bit more. Place your side surrounds on stands at the sides of your couch, but bring them more forward for spatial separation. You want to place them about at the center-point of your Love-seat/L-section of your couch. Turn them so they aim at the center of the main seating position. Also, if you can, move your couch a bit to the right, maybe center it on the wall a bit, or line of the right side of the couch with the edge of the wall behind it. That should give you plenty of room for your side surrounds.

Give that a try and see if you like it. Later, if you feel like downgrading from 7.1 to 5.1 I would recommend placing your surrounds in the back left corner and next to the edge of the wall just behind your couch but again, angled to the center of your seating position. I would try the 7.1 as I have suggested first though.