Create our Progressive Web Application to replace our existing apps

We have an Android and iOS App for our business, and we want to replace it with a single PWA to reduce ongoing development costs. Our current apps are designed for our workforce to download in order to receive job offers and submit timesheets. The good news is you will be developing the PWA with the existing product in existance making the development process much simpler. We will be seeking to make some improvements.
We are seeking a development team that is large enough to lean on expertise such as SQL, Java and Symfony, as other parts of our web application are built using Java and Symfony and these need to be understood. The web application is quite old using a lot of stored procedures, so we would look to extend our mobile app conversion to the broader web application with the right company.