OK, this sort of situation occurs more often that some of us would like. But hey, its the real world.
This is my opinion, and my advice:
1) Forget 7.1.
2) I believe the best option is to think of one ideal sweet spot, and screw all other positions. For then you would at least have one good spot. I believe compromising for that other seat will be too compromised for ALL positions. Hey, the wife can always join you on the couch.
- if doing the other orange circle, its simply too far ahead of the main viewing position.
So, my advice is to use a 5.1 system, and place the side surrounds either at the present spots they are slated for, or exactly where the rears speakers are.
Having both sets is pretty pointless, IMO, and actually might harm more than hurt.
If you don't believe me, you can spend some hours searching thru AVS threads/queries with similar setups. In fact, you will invariably find that others are harsher than I am.
If you TRULY want to compromise in the best way for ALL positions, I would then recommend a 3.1 system. However, I don't think that's what you want. I recommend 5.1.
Good luck on getting good advice.
Happy Turkey Day.