Don't know where to buy it but that should be an easy thing to knock off. The mirrors would be easy enough to find at Hobby Lobby or Michael's - some place like that. There are a gazillion types of wire - can't tell for sure what that is but it's a soft wire, easy to bend and it's a rather random design. They probably bent it around 2 or 3 different sized forms. I'd wing it and make my own. Here is a link that might be useful: Wire on Amazon

In many mid to higher end furniture stores you can pick the upholstery fabric that you want for a particular couch and they will have it made for you. Ethan Allen does this, and I'm sure there are many others. You can shop online, but I would suggest finding a store where you can look at the fabric swatches in person and talk to a consultant about your options. Edited to add: going this route can be kind of expensive, and I just re-read your post and saw your note about trying to avoid that.... sorry

I would be going off of reviews and recommendations and I know that isn’t ideal. However, I‘m only looking to buy one sofa so I would rather cut out the middleman if possible.

I'm currently searching for a sofa set and I'm leaning toward Flexsteel myself. My research has shown me that they seem to wear well over all and last very long. I'm in the midwest and purchased a set from Value City in 2014, and the power reclining mechanism is still going super strong, but the dual seat sofa has become flat at the back and we can feel the wood, and the seats have become flat in the middle and all you can feel is the metal bar. We had to stuff one of the cushions it came with and it's still uncomfortable.