vishwajit_shind- Before moving onto the custom component for the message list, have you considered that you'll loose many OOB features, such as batch processing, subscribing etc. As an option, you can contact Lithium support and get some edits to the existing component to look like your new design. They will add few grids and then you can add your code to it. You'll need to share your designs etc.
Otherwise, there would be too many conditions to handle, the floating threads, icons etc. Here is an option of OOB boards page with new design. https://community.opentable.com/t5/Gift-Cards/bd-p/ot-gifts
I hope this helps.
