Wood burning fireplace insert on old brick fireplace

[Littlehello]

I live in New York and my house never seems warm enough for me. I would like to install a wood-burning fireplace insert into an old brick fireplace. Before I start inquiring with local businesses can anyone look at this picture and tell me if anything stands out to you as problematic for something like this? Thanks in advance.

 

[begreen]

The fireplace looks small and the hearth might need changing to afford proper floor protection in front. Depending on what might fit, the latter issue may be easy to solve.

How large is the fireplace opening? What is the depth, top and bottom?