That way sounds fine just want to make sure that you have a rubber mat under the fuel cell as well as making sure it will not slide side to side. What I would do is maount little "L" brackets so that the cell fits inside them to prevent it from moving at all. Also making sure that you have rubber between the brackets and the cell as well. All this is my own opinion and something that I would do and also a suggestion due to there being more than one possible way to mount it. I am sure that others will speak up and give other suggestions from their experiences or seeing it done other ways.