Moodle Development - Medium to Long Term

We would like to move our LMS users on to Moodle and/or Moodle workplace and would want you to help us undertake this for us, i..e creation of a new template for us for the look and feel, as well as plugin and functionality development on Moodle. We also have our own Authoring tool which we would want to integrate into Moodle and would want your help to build this plugin for the integration. Also we have 350k learners on our end of life LMS. We would want to migrate to Moodle so help scripting that migration would be in scope too. Internally we have our own development team and we are focussing on our authoring tool development and would want you to work in collaboration with them on the Moodle side while we focus on our authoring tool. We would like to experienced Moodle developers working on this work for a medium to long term period of time to help us build this.