Need billing info fields to appear by default within main body of product page

Everyone knows that on Shopify, a typical product page, even when a site sells only one item, still must have a BUY NOW button, which then takes the person to a checkout page or it opens in a sidebar.

On a different platform, I had much better conversions when the customer lands on the product page, sees photos and reads the product description, and directly below those all the ‘enter payment’ details fields are already right there waiting to be filled in. No sidebar, no page refresh to a a checkout.

I’d like help making this a reality on our site. We currently use the Debut Shopify Theme. I have a different unrelated site that uses Theme Forest, and it is because of that which I wondered if a developer from here could help us modify the Debut Theme. And if not, we would consider switching to a new modified theme if that is the only option.

Please reply there if possible. If it is not possible we will try to remember to check back here on occasion.