I am new here, but here is my 2 cents worth.....
I personally wouldn't go with a side by side cage option. Macaw beaks are large and you just never know what might happen to toes that are peaking through the bars, etc. I had the opportunity to foster a BG many years back. I wish I had adopted him and not just fostered him because I really grew to love that big goof ball. He bonded with me and regurged for me several times a day :eek:
I say that if your both comfortable with the idea, have the time and love to devote to adding another and are financially able, then go for it. BG's are fantastic, lovable fids!