Hi @Kevin11942
Welcome to the Sonos Community!
I think a pair of Era 300s would significantly improve your Home Theatre experience here, and more so than any other options.
Assuming you are a fan of symmetry, I recommend wall mounting them just under or - better - slightly-under-and-to-the-outsides of the wall sconces. Putting them more to the outside would reduce the possibility of literal headbanging (assuming you tend to sit in the middle), but you do want them to be roughly at head-height.
The pillar may obstruct the virtualisation of the right side channel slightly, but I think TruePlay Tuning will make light work of that, assuming you have an iPhone or iPad to do the tuning with. Even without, you probably won’t notice.
Finally, I hope you have a dimmer for those six lights to use on movie nights!
I hope this helps.