i phone 4s water damaged beyond repair

Hi everyone, perhaps someone can help with my dilemma. Much loved i phone 4s was dropped down the loo....exactly. It's damaged beyond repair. My problem is finding a replacement. The phone was bought by my daughter from her older brother, and was a much prized possession. It had 64gb and was priceless to her. Her birthday's coming up and I'd love to find a way to get another one for her, but they aren't around anymore. Can anyone suggest a solution? Any site I could buy a refurbished one for her, that would be trustworthy?

Any help would be much appreciated.